Episode 17 of the Modern Chemistry podcast features Dr. Amanda Morris, Associate Chair and Professor of Chemistry and the Patricia Caldwell faculty fellow at Virginia Tech. In addition, Amanda is an associate editor of Chemical Physics Reviews, editorial advisory board member for ACS Applied Energy, Materials and Energy Chemistry, as well as being an ACS (American Chemistry Society) expert in sustainable energy. .
Amanda has a BS degree in Chemistry from Penn State University, and PhD in Chemistry from Johns Hopkins University and conducted post-doctoral research at Princeton University prior to her tenure at Virginia Tech.
Amanda’s research focuses on how to convert solar power into usable energy, or fuel, and useful materials or chemicals
You will hear the following terms used during the interview. I've included some descriptions here.
Amanda is contactable on social media, and you can find them via on
LinkedIn https://www.linkedin.com/in/amanda-morris-1a11b621/
Amanda is @amorri28 on Twitter - https://twitter.com/amorri28
Amanda’s lab page at Virginia Tech is https://chem.vt.edu/people/faculty/teaching-and-research/amorris.html – a great starting point for more information.
Our theme music is "Wholesome" by Kevin MacLeod (https://incompetech.com)
Music from https://filmmusic.io
License: CC BY (http://creativecommons.org/licenses/by/4.0/)
Connect with me (Paul) at https://www.linkedin.com/in/paulorange/
H.E.L. group can be found at www.helgroup.com online,
on LinkedIn at https://www.linkedin.com/company/hel-group/
on Twitter, we're @hel_group, https://twitter.com/hel_group
or search for us on Facebook
This transcript was produced by Rev.com - no further proofing or checking of the transcript has been conducted.
Paul Orange (00:09):
Hello, and welcome to the Modern Chemistry podcast with your host, Paul Orange. Hello and welcome to episode number 17 of the Modern Chemistry podcast. This is our first show of 2022, so I hope we find you safe and well and that the new year is treating you well. Our guest for this first episode of our 2022 run is Amanda Morris. Amanda is professor of chemistry at Virginia Tech. And we're gonna jump straight into a little bit of the sort of the pre-recording discussion that Amanda and I were having. And I left this in the show today, because it talks a little bit more about some of the practical details of what Amanda and her group are doing, some of the techniques they using, um, and then you'll hear us kind of segue into the show proper after I do the sort of official intro thing.
Paul Orange (01:02):
Amanda and I recorded this podcast at the beginning of January 2022. Uh, we were over Zoom. And it was at the same time as the COP26 conference was going on in Glasgow, which felt like really good timing considering the main thrust of, uh, the work that we discuss and what Amanda is working on is how to harness solar power to create energy in useful products. And I think, one of the things that really comes out of this discussion is almost an answer to that question. If you've ever wondered why don't scientists just dot dot dot... whatever that dot dot dot is, I think Amanda really articulates exceptionally well the considerations that need to be made from the science of today into the industrial or everyday applications of tomorrow. So I think if you listen to it from that point of view, you'll get a lot out of it, uh, as well as listening, uh, to- about the science. So with that, I will just hand over and we'll go straight into the conversation we had with Amanda, and I'll be right back at the end. Enjoy.
Amanda Morris (02:11):
I know that you guys are reaching out 'cause we have one of your-
Paul Orange (02:13):
Mm-hmm (affirmative).
Amanda Morris (02:13):
... um, high pressure systems. Um, you know we're using that for CE2 hydrogenation, right? So I think that that's probably, uh, pretty common for-
Paul Orange (02:25):
Yeah.
Amanda Morris (02:25):
... what people are using your system for.
Paul Orange (02:26):
Yeah, mm-hmm (affirmative).
Amanda Morris (02:28):
Um, uh, how we're using it is- is my group focuses on porous material, specifically metal–organic frameworks, I don't know if you've heard of what thos are.
Paul Orange (02:36):
I've- I've written them down in my notes, so...
Amanda Morris (02:39):
Um, anyway so we're- we're trying to develop, everyone hates the word "novel", but novel metal–organic frameworks, uh, for CO2 hydrogenation. And I can kind of give a background on people who are working in that area. We're not the first to kind of, uh, dip our toe there.
Paul Orange (02:56):
So, this time on the show I'm delighted to welcome Amanda Morris who's the professor of chemistry at Virginia Tech and is also the [inaudible 00:03:04] faculty fellow. Uh, Amanda, welcome to the show. Great to have you here.
Amanda Morris (03:08):
Great to be here!
Paul Orange (03:10):
Uh, Amanda, maybe starting at a- at a really high level about the work you're doing. And we try and talk about how chemistry has an impact on the modern- modern life. A term I've come across a few times when looking into your publications is artificial photosynthesis, and I think that's a really great point to- to start from. Is- do you see that as the- insular end goal of your- of your work? Or is that just a term that gets kind of associated with, uh, you know that sort of solar energy conversion?
Amanda Morris (03:37):
Oh, I mean artificial photosynthesis is a very complex process. Um, and as we talk today we probably can get into all of that. But I would love to, 20 years from now, have my work inspire a widget that is actually able to do the process of artificial photosynthesis.
Paul Orange (03:52):
Mm-hmm (affirmative).
Amanda Morris (03:53):
But as a chemist, right, we're focused very much on the- the fundamentals, um, of that. But- but there are obvious reasons why artificial photosynthesis must play a role in, um, future economies.
Paul Orange (04:06):
And the goal for the artificial photosynthesis then really is this concept of driving clean energy and- and driving that from basically the sunlight that hits the earth? Because that provides more energy than we need or I think, uh, probably paraphrasing something I've read on your- on your website or in one of your papers, but-
Amanda Morris (04:26):
One and a half hours.
Paul Orange (04:26):
Yeah.
Amanda Morris (04:28):
Yeah, one- in one and a half hours, enough solar energy hits the earth's surface to power the entire swathe of human civilization for an entire year. Now- now of course, I always say to my students that like you could imagine like you wheel out your solar panels for your hour and a half, and like you collect all the energy you need and then like wheel them back into your basement and you don't have to worry about it 'cause we've just stored it. And that's really not possible. Which is why other technologies are needed, right? Technologies like batteries, technologies like artificial photosynthesis. However ar- I view artificial photosynthesis as even a broader concept than just fuel. You're absolutely right. Like when we think about natural photosynthesis, it takes carbon dioxide and water and converts it into sugar, which is our fuel, right? And that's how we power ourselves through the day. And sure, we can re-envision that system to generate things that we as humans use as fuel. So we could make with water and CO2 some carbon-based fuel that we could then pump into our vehicles and drive down the road. Um, and that would be great.
Amanda Morris (05:28):
But there are lots of other places where we can use carbon. Um, right? So we can use artificial photosynthesis to make polymer precursors, right? I mean plastics are everywhere. I'm sure you can look around your desk right now and point to about six or seven plastic things, right?
Paul Orange (05:42):
Yeah.
Amanda Morris (05:42):
Um... and so, if we could, instead, through the use of solar energy, which is sustainable, generate other commodity chemicals that we need to run our daily life, that also has incredible value. Just- just a point for your- your readers, and I think this is a- a thing that we often don't talk about in artificial photosynthetic world, I just made it sound really great. Like that we can make carbon-based fuels and drive our vehicles down using solar powered fuel and, um, make all of the stuff that we use, so all of the- the- the- the carbon containing polymers that are in our clothes and in our phones and all of that. But, it turns out that if we were to use all of the extra, and I mean extra, so excess CO2 over historic levels, and convert that into fuels or commodity chemicals, we would immediately wash out every market. And we would make the product useless 'cause we'd have too much of it. In general, when I talk about artificial photosynthesis and I say, you know, "This is so great, it could do this", it can only really manage about 17 percent of the carbon that is in the atmosphere. And so when we're talking about sustainable energy generation or sustainable product generation, we do need to be aware of kind of the limitations of that.
Paul Orange (07:02):
Mm-hmm (affirmative). When you talk about using CO2 then to sort of capture this energy, what are some of the challenges of using s- uh, CO2, you know, to- to provide energy to- I guess to sort of like power your- or- or to provide the energy out of your solar powered CO2 battery?
Amanda Morris (07:20):
Right. Um, I mean there's lots of issues with CO2. So here's the thing: CO2's a very stable molecule. And, uh, unfortunately when you wanna convert a stable molecule into something that you can use as a fuel, that's a pretty difficult process. And so, we need to develop catalysts, which is part of what, um, my team does, that's actually capable of converting CO2 into these useful chemicals. And that, you know, is- is a huge challenge. A huge challenge not only from the perspective of the stability of the molecule, so it requires a lot of energy to do that, but also the CO2 can be reduced into so many things. I just told you that's a great thing, right? We can reduce CO2 to fuels, we can reduce it to polymer precursors, we can reduce it... right? That's great. But the problem is that as a chemist, I need to give you a process that gives you one single product, right?
Paul Orange (08:11):
Mm-hmm (affirmative).
Amanda Morris (08:11):
And unfortunately, a lot of the processes that we have give you up to 32 different products, right? So-
Paul Orange (08:19):
Right.
Amanda Morris (08:19):
... uh, the most efficient catalyst for CO2 reduction right now is just actually copper. Surprising. But- but unfortunately, as I mentioned, it gives 32 distinct products that have been identified when operating. So from an engineering perspective then that becomes a nightmare, right? 'Cause you have to separate 32 things, right? And so, uh, we kind of have this challenge in utilization of CO2 of the energy required to actually do the process on a stable molecule. And then we also have this issue that we can convert it into lots of things. So we need to have things that work, uh, highly efficiently as catalysts to lower the energy required, but they also need to be very selective. So we need to make one single product from- from the process.
Paul Orange (09:08):
So how do you go about taking, you know, copper, very abundant material, used all over the place, how do you then start going through that process of getting the selectivity and also, 'cause you said the- the efficiency of the process? And, you know, you- you're taking something that feels quite esoteric, right? You know, sunshine hits a sur- surface and somehow there's- there's magic made, whether it's a- a fuel, a polymer or, you know, something that's an electricity store. Uh, wh- where do you even start?
Amanda Morris (09:39):
I- I'm gonna be honest. With copper, I have no idea, right? It's a- it's a heterogeneous surface, right, um, uh, and we don't have, at this point, a really good way to control things at those surfaces. I mean anybody who works with surface science, and I am- I'm not someone who works in surface science, will tell you that we don't really understand the vast majority of chemistry that occurs at solid surfaces because we don't have good techniques to monitor what's happening at that very small, small level. And you often get kind of a mixture of things and multiple different pathways can be a current. And so for copper itself, I don't really have a good idea. There are people out there who are working on it, so really, really awesome work coming out of Christopher Earle the University of Nevada, Reno. And what he's done is he's put, uh, polymers on the surface of copper. And he's shown that by changing the thickness of the polymer and perhaps the identity of the polymer, you can now make it selective to one thing. Like, super cool, right?
Amanda Morris (10:39):
You know, and then of course there's lots of people who are saying "Well maybe copper's not it. Maybe copper works at low energy but maybe because it's not selective, maybe we should be going to something else". So then there's this whole group in California who is working on basically mixing lots of different metals together. Getting away from just copper or a chunk of iron or whatever, and mixing three metals together in this heterogeneous surface and trying to make things that operate at low energy and are selective. So that's all really awesome. That isn't the area I work in (laughs).
Paul Orange (11:09):
(laughs).
Amanda Morris (11:09):
And the reason that I don't- I don't work on that is 'cause I come from a molecular chemistry background. In- in contrast to kind of these heterogeneous chunks of metals, when we think about small molecules, there are lots of handles that we have there that can create selective catalysts. There's a central metal that we can change, and then there's all the periphery around that central metal. So those are typically called ligands. And so we can put things on those ligands to stabilize certain intermediates, to push reaction certain ways, and we can also, uh, lower energy barriers by doing that. So all of those things, all of those handles that molecules give you, I really love. We don't have that, right, in the heterogeneous field perse. But in the molecular field, I can very easily change a ligand scaffold, uh, via synthetic means, and look at those changes to mechanism, and then learn how I'm controlling selectivity for CO2 reduction and then create a better catalyst. Um, and so I really love, love molecular chemistry because of that.
Amanda Morris (12:12):
Now of course, there's gotta be a problem, right? Because if it was so great, we could modify mechanisms, why don't we have a solution already? And the issue comes with the negative from molecules, which is stability. So copper as a chunk of copper will work pretty much forever unless it gets poisoned by, say, carbon monoxide or something, right? But molecules, on the other hand, tend to fall apart very quickly. And so the- the amount of times you can use the catalyst, and which to be a catalyst you have to use it more than once, so it has to drive CO2 reduction once and then drive CO2 reduction again. Then it is the definition of a catalyst. But that how many times I use it is called a turnover [inaudible 00:12:53]. Um, and so that's how we define that in the field. So it's how many times a catalyst does the reaction over again. Uh, and there are catalysts our there that operated with turnover numbers of four.
Paul Orange (13:06):
Oh, right.
Amanda Morris (13:06):
Which is [inaudible 00:13:06] the reaction four times.
Paul Orange (13:08):
Mm-hmm (affirmative).
Amanda Morris (13:08):
And then the catalyst is dead, right? I mean nobody from an industrial perspective is gonna go, "Oh yes, let me invest in that!", right? And so it's a huge challenge on the molecular side to figure out how to make things as stable as a chunk of copper.
Paul Orange (13:23):
So when you- when you look at some of these catalysts with these lower turnover numbers then, what would be... uh, uh, a- a goal? Is 10 good? Is 100? Is 1000? 'Cause I mean we're thinking about something energy wise, like a comparable thing might be a rechargeable battery, right? How many times can I recharge a rechargeable battery? It's four times, I'm probably not gonna pay the premium, but if it's 100 times, yeah maybe. And also, what's- what are the goals there?
Amanda Morris (13:50):
Hmm. So industrial catalysts currently have turnover numbers in the millions.
Paul Orange (13:57):
Right, okay (laughs).
Amanda Morris (13:58):
Right?
Paul Orange (13:58):
Yeah.
Amanda Morris (14:00):
So we're- we're way off, right?
Paul Orange (14:02):
Yeah.
Amanda Morris (14:04):
There's a big difference there. So- so yeah, um... you- you've gotta be in the millions to really make it relevant. And so, you- you know, like I said, that's why we're chemists and we're kind of working in this fundamental field. We're trying to understand, well what thing did make it better? This thing made it better. Okay, well this catalyst isn't stable but maybe somebody can use that same thing that we added to it to make it better in their catalyst, which is more stable, and that will make that catalyst better. So it's really the whole field has to kind of work together to kind of prop- prop ourselves up and get to those- those set points that we're- we're interested in.
Paul Orange (14:40):
On then a day to day basis, you're taking your- your catalysts and these are MOS, which is, uh, metallo-organic frameworks if my research is good, and you're iterating these and- and looking for better performing molecules?
Amanda Morris (14:57):
Yeah, so I guess I should clarify what- what metal-organic frameworks are. So- so, um, I mentioned heterogeneous systems and how they're really great 'cause they're stable. They also are in a different phase than the reaction, right? Which makes separation of the catalyst very easy at the end of a process. So- so from an industrial perspective, everybody loves solid state things. That's why the vast majority of catalysts that you have in industry are nano particle, solid things that are attached to surfaces. So that's wonderful from a heterogeneous side, although not selective. From the molecular side we've got this issue of stability. And we've also got this issue that it's typically in the same phase as the reaction. So if I'm doing CO2 reduction in solution, the catalyst is there, and so even if I make product, that's wonderful, but it's mixed in, right, with catalyst.
Paul Orange (15:42):
Right, yeah.
Amanda Morris (15:43):
So then I've got to separate the catalyst off, so that's a mission. But molecular systems give us selectivity. So we've got these two camps. We've got this heterogeneous stable thing, really good separation. We've got this molecular system which is selective but doesn't have those other pieces. What metal-organic frameworks do is they actually give us an ability to bring those two fields together. So metal-organic frameworks are solid materials. They're chunks, you know, like I- when we make them, they're typically powders. Um, so I could show you and it would look kind of like, um, well it depends on- on what it's doing, but it could look like flour, right?
Paul Orange (16:19):
Mm-hmm (affirmative).
Amanda Morris (16:20):
So you [inaudible 00:16:20] oh yeah, I see that, it's solid. And when we put it into a solution it stays in its solid form, so it doesn't dissolve in water, it's a solid chunk, just like copper, a solid chunk of copper. But, when you dive down into those individual particles of metal-organic framework, they're molecular. So what they are, are these inorganic clusters, um, which we call nodes, that are connected by organic linkers, and the organic linkers can be those ligands that I talked about on catalysts. And because the linkers are able to basically form extended structures, we make kind of a three dimensional molecular solid state polymer. Super cool. Again, not w- I didn't create metal-organic frameworks, right? So there's lots of people that- that came before me in that field. But, these structures are awesome, because what I can do is I can make molecules, I have all the synthetic handles that I had on the molecular side, so I can add different spinach to stuff to make it work better and change energetics. But I also can centrifuge the stuff out of solution and separate it from the reaction, right?
Amanda Morris (17:29):
And metal-organic frameworks have shown to increase the stability of molecular catalysts. And so we've shown this in the- in our literature as well. We've been talking a lot about CO2 reduction, but to reduce CO2, this is a- a- kind of a complex idea, but to reduce CO2 you give it electrons. So that's- that's what reduction means, you're giving it an electron. If I'm giving it an electron, right, electrons are not like out there in the world. I can't buy from a company a bottle of electrons. I can't be like, "Oh send me electrons", and I just mix 'em in with CO2, right? I have to get the electrons from somewhere. And where photosynthesis gets electrons from is water. It's a really great idea. Water's super abundant, right? So why not get electrons from water? And so, uh, we in our lab have worked on oxidizing water, that is taking electrons out of water. And we've used a catalyst that in solution, a molecular catalyst, that in solution dies in about 30 minutes. And we've been able to show that that catalyst, when incorporated into a metal-organic framework, now, it could last for longer, it's just my students stopped at six hours. So it can run for six hours, right?
Paul Orange (18:40):
Mm-hmm (affirmative).
Amanda Morris (18:41):
By putting it into the metal-organic framework. So, you know, that's great. 'Cause now what we're doing is we're bringing together the stability of heterogeneous systems with the synthetic trainability of molecular systems in really this great marriage of metal-organic frameworks. And so that's- you- you know, that's why I work with those materials specifically, 'cause I think it's bringing together the best parts of both of those worlds.
Paul Orange (19:06):
Mm-hmm (affirmative). And what sort of the conditions are the reactions happening in? Because earlier on you sort of mentioned, be great if there was a widget where you [inaudible 00:19:11] the sun and charges a battery or something. But is it working at ambient temperatures and pressures? Or are they elevated? How's- you know, how- what- what's- what- what's- what's your current experimental protocol like?
Amanda Morris (19:23):
Right now for, uh, for kind of an ideal system, what you'd wanna be operating in is in water. There's a lot of controversy as to what pH that water should be. You can play with pH to make certain reactions easier. So if I operate at basic pH, the water oxidation side becomes easier. If I operate at acidic pH, sometimes I can make the CO2 reduction side easier. Although I also cause some additional reactions to pop up, which is problematic. So there's a- there's a big controversy as to what conditions of water you should be in. The- the classic first example really of, uh, something called water splitting, which is a version of kind of early artificial photosynthesis, I define artificial photosynthesis as something that utilizes CO2, but if you don't reduce CO2 and say you reduce protons to hydrogen, hydrogen is also a fuel, right? We could use that. That process is called water splitting. So you oxidize water and then reduce protons to hydrogen.
Amanda Morris (20:23):
The first example of this by Fujishima, the Honda, actually played with this pH difference. So they put one side and they put the water oxidation side in basic pH, and they separated it by a polymer membrane, and then they put the reduction side in acidic pH, right? So they really biased the thermodynamics of that system to work because they made water oxidation as easy as they could and they made proton reduction as easy as they could. Ultimately, for an industrial process, you want both of those to operate at the same pH. And that's super problematic. We don't really have catalysts that work on the one side really well and the other side really well and [inaudible 00:21:00]. So there's still controversy as to where you wanna- wanna run it.
Amanda Morris (21:04):
A lot of people talk about doing it at neutral pH. I think from an industrial perspective, that makes more sense. It's- it's much easier for me to put just pure water in there than to work a- worry about acidifying or baseifying that system. But- but in the chemist's world, we're kind of like "Well, let's get something that works first, and then we'll worry about what solution conditions we're in". So- so I would say you would want water, right? So that's the first thing. Everything that we do is at room temperature. Um, or- or we tend to do things at room temperature. Or as low as temperature as possible. So- so some of the stuff that we are doing is at slightly elevated temperature, like 60 degrees celsius. But we're- we're really not pumping really high temperatures into things. And then pressures, it depends, right? It really depends on what- what you're interested in doing, right? Ideally, so I'm gonna go to the ideal situation, what you'd wanna work with is atmospheric pressure.
Paul Orange (21:58):
Right.
Amanda Morris (21:58):
But there's a problem with that, in that while we talk about so much CO2 in the atmosphere, it's really only 400 something parts per million. And when you think about how much of that CO2 is then dissolved in solution, so it- when you have water in the presence of the atmosphere, some of the CO2 that's in the atmosphere is also in the water. And so there's some concentration of CO2 in that water. And so you'd obviously, under an ideal situation, wanna just be able to turnover in the CO2 concentration that's made of [inaudible 00:22:27] and water. That's a very low concentration.
Paul Orange (22:30):
Mm-hmm (affirmative).
Amanda Morris (22:31):
Than from just availability of substrate, availability of thing you wanna work with, in your system is very low. And so a lot of times we're working with pressurized CO2 systems to increase the amount of CO2 that's dissolved. So like in my lab, we'll operate a lot of times under one atmosphere of CO2. So that's like I took the whole world and got rid of all oxygen and nitrogen and just had CO2, right? So if I put just CO2 over water, more of the CO2 will go into that water, and that will increase my concentration of dissolved CO2. So yeah, so- so, you know, we're often working at- at kind of one atmosphere. Although we do go to higher concentrations, and other- higher pressures of CO2 for- for other applications.
Paul Orange (23:13):
Hmm. Going back to what you said earlier, you know, you took, you know, that- that 14 percent I think you said of excess carbon out of the atmosphere, um, and your- somehow that powered every need that we have for humanity. Does that 14 percent basically then get recycled? So it gets reduced and the oxidized and then re-reduced again? So you're kind of... you know, you're basically fill your widget up and hopefully it just keeps on running and doesn't need any other maintenance?
Amanda Morris (23:40):
Yeah, so- so it's 17 percent. And you're absolutely right. Yes, the idea would be that if you were to operate the artificial photosynthetic system and then couple that to, say, a- a combustion type engine, you would reduce CO2 into the fuel, then you'd burn the fuel, create CO2, you'd take the CO2 back into the system, and it would be basically a- a closed loop cycle.
Paul Orange (24:02):
Right.
Amanda Morris (24:03):
Um, and so we wouldn't put any more CO2 into that- the atmosphere. But of course we can only take out 17 percent of what we've already put in.
Paul Orange (24:14):
Right, but- but I'm guessing what you were also saying about the broader technologies here, we're- you know, we're just talking about energy, you then also got potentially taking some of that CO2 out to turn it into other useful things, all the plastics and polymers we need. Or converting it into that even just to store it back underground for instance. I- I think there, you know, everyone at COP26 would be pretty happy if they could take 17 percent of the excess carbon out the atmosphere tomorrow, right? So it's a huge step forward.
Amanda Morris (24:43):
Right.
Paul Orange (24:43):
It's a huge step forward. And do- I mean, I don't know if this is an unfair question, but because the term artificial photosynthesis is used, ho- how much does this borrow from photosynthesis that happens inside the cell of a plant? Or is it really the- just the concept of taking solar energy or light energy directly and turning it into an energy storage medium?
Amanda Morris (25:06):
You know, I think it really depends on- on what kind of system you're working with and how- how much you envision that that looks like natural photosynthesis. Obviously, natural photosynthesis is made up of a bunch of proteins that are embedded in a membrane, right?
Paul Orange (25:18):
Hmm.
Amanda Morris (25:19):
And- and each one of these components has their- their job and they work beautifully in concert and then magically do this. And I say all of that, but natural photosynthesis is incredibly inefficient. Most systems operate about three percent, right? So I mean like you from an industrial per- you're- or an em- you're not gonna buy a three percent efficient system, but that's what plants are doing it at. They're doing it at three percent. And then they all- and nature also has this ability issue. The side of natural photosynthesis that does water oxidation falls apart all the time. All the time. It operates very quickly, but it's turnover number is very low. And so, luckily for nature, it's got something else that's gonna come back and rebuild it every few minutes, right? But from an industrial perspective, I couldn't take natural photosynthesis out of a plant and put it in a beaker and then sell it to you to actually operate. This doesn't- it's irrelevant.
Amanda Morris (26:10):
And so w- w- where is the inspiration that we take from nature to call it artificial photosynthesis? Well, the- there's a bunch of different places where you can go to. So for example, when we use metal-organic frameworks for artificial photosynthesis, one of the things that you have to do is you have to harness solar photons, right? I mean I have to be able to have this system interact with solar photons and create electrons and holes to do the reduction and to do the oxidation. Nature, if you go and look at actual photosynthetic proteins, so these are like the chlorophyll that make plants grow. When you go and look at how nature puts these together, they're beautiful. It's like these concentric rings of chlorophyll that are all connected to each other kind of and they're really, uh, closely spaced perfectly and they're at the right angle and all of this stuff. Nature has taken eons to evolve these beautiful systems where you take these light harvesting molecules and orient them in three dimensional space so that you harness solar photons incredibly efficiently.
Amanda Morris (27:11):
When we use metal-organic frameworks, I mentioned that these are three dimensional molecular polymers, what that allows me to do is it allows me to orient things in three dimensional space, right? I can, based on the structure of that polymer, change how the [inaudible 00:27:28] are oriented to each other, their spacing, and what they look like. And so, from my perspective in that area, we're very closely trying to mimic what nature does, right? We're trying to figure out how to orient these chlorophyll like molecules within perfect distance to each other and perfect orientation and all of that to be able to harness that light effectively. And so I would say that that's very bio-inspired, right?
Paul Orange (27:53):
Yeah.
Amanda Morris (27:53):
It's very close to what artificial photosynthesis wants to do. But if you took a picture of my material and put it next to the- the protein, they would look nothing alike. You know? So is that truly bio-inspi- I mean, I don't- I don't know. But I mean I- I'm trying to understand why nature did what it did and do it in a system where I can actually synthetically make it, if that makes sense. And there's lots of other examples. For- for water oxidation, for example, I mentioned that the catalyst falls apart a lot, which it does, which is not good. But it operates very fast (laughs). Um, and so it's oxidizing water just so rapidly that we would really like to as- as chemists figure out how to make things that operate that rapidly. Now I will say, we are there. We do have things that operate as rapidly as the- the water oxidation catalyst of- of m- real photosynthesis. Although that's a more recent discovery, you know, in the last 10 years.
Amanda Morris (28:46):
But people looked at what nature's water oxidation system is, and it's basically a- a cluster of manganese and calcium bridged together by oxygen, and they're like "Oh, well, you know, that looks kind of like metal oxides or little metal oxo clusters. And- and so I can start to develop metal oxo clusters". And so that's what people did, they started to think about these, there's these manganese cubane clusters that were developed at Yale that, you know, very closely kind of look like what nature does. And so they're able to make these. You know, there's the very famous kind of cobalt phosphate films of Dan Nocera and others who worked on cobalt oxides before that. That those also are kind of these molecular little, now not manganese, but cobalt oxygen clusters that are also able to oxidize water very rapidly. And so, again, if you held them up next to natural photosynthesis, it doesn't really look the same, but we're taking inspiration from what nature does and trying to find out if we do that in something that we can make, can it actually work?
Amanda Morris (29:49):
And so there's- there's a lot of bio-inspired nature to artificial photosynthesis. But I'm never gonna make something that's embedded in a protein, right? With crazy spinach around it, right? So it's never gonna look like natural photosynthesis.
Paul Orange (30:01):
Mm-hmm (affirmative).
Amanda Morris (30:02):
But I'm gonna take lessons from nature to develop a [inaudible 00:30:04].
Paul Orange (30:03):
And that just sort of sparked something in my mind. You talked about, you know, capturing solar photons. So, how do you control for that in your experiments? I mean do you- I- I mean, assuming you just don't run these, like, sort of sit them outside the lab on the- on the sidewalk and run them? Or probably a silly question, but do you have-
Amanda Morris (30:21):
No, no, no, it's not.
Paul Orange (30:21):
... control conditions or, you know, how do you-
Amanda Morris (30:23):
No it's- it's absolutely relevant. Absolutely relevant. No, of course, I- I can't put it out on the sidewalk and measure because, uh, today there's- it's cloudy-
Paul Orange (30:32):
Mm-hmm (affirmative).
Amanda Morris (30:33):
... outside. I would probably have pretty low efficiency to whatever I'm looking at (laughs).
Paul Orange (30:37):
(laughs).
Amanda Morris (30:37):
Uh, and that wouldn't be good. Uh and then we can't just wait until summer and be like "Oh, this is when we're gonna do all of our experiments. It's a nice day".
Paul Orange (30:44):
Yeah.
Amanda Morris (30:45):
And so, uh, we have controlled lights that have filters in front of them that actually mimic the solar spectrum. And so there's these kind of, uh, lamps that are called- that have AM 1.5 which is basically a- tells you about like what kind of atmosphere the light is passing through, so you know how to filter it so that it looks like sunlight. Amazingly enough, the vast majority of those are kind of tuned to the solar spectrum that hits, you know, near Denver, Colorado. Right? And you're like why- why Denver, Colorado? Turns out that that's where, uh, the National Renewable Energy's Lab is. And so if you actually create a solar cell and you want to get the efficiency of that solar device, uh, certified, you send it to NREL. Or at least in the United States, that's where you send it.
Paul Orange (31:31):
Mm-hmm (affirmative).
Amanda Morris (31:32):
And then they certify it based on their light source. And so really to standardize things we use these. The solar simulators, they're called, so you can Google them and you'll see, it just basically looks like a fancy lamp.
Paul Orange (31:44):
In my reading around, I picked on quite a- a- a bit in terms of the publications you've gotten to talk about reducing CO2 but then also you talk about reducing other, is the first thing like hydrocarbon substrates as- as well? Using these frameworks. It's more than just pure energy generation, right? It's just harnessing that solar energy for a- a useful end product. I mean how do you see that sort of, you know, strategically in- in your lab? Do you- do you have a focus on energy or do you have a focus on the sort of- the conversion of a thing into a useful other thing?
Amanda Morris (32:20):
Right? It's the other piece. So I talked about that 17 percent. So you've got this percentage that- that could go to fuel.
Paul Orange (32:25):
Mm-hmm (affirmative).
Amanda Morris (32:25):
We need a solution there. But we've got this percentage that could go to all of the other stuff that we use. And so that should also be something we look at. And so, yeah, I have, you know, I think it's pretty standard that- that PIs or principal investigators, people who are running labs, have grants from different agencies. And so from the department of energy, I am funded to figure out how to make fuel, right? 'Cause that's what they care about, right? They care about understanding how to make a carbon neutral fuel cycle, right? That would be an incredible breakthrough for them. They're not so interested, I mean they kind of are, because obviously energy is used in every process. So if we could convert other processes to using solar energy, that would be of benefit. But, um, I actually am funded through the national science foundation to figure out how to make these polymer precursors.
Amanda Morris (33:13):
So you know I have two different kind of thrusts in the group where I've got my- I should say, I have a lot more people on the energy side than I do on the polymer precursor side. But, you know, I've got these two kind of camps. Now of course they talk to each other, right? And there's things that we can learn from each of those things.
Paul Orange (33:28):
Mm-hmm (affirmative).
Amanda Morris (33:28):
Um, but they're fundamentally working with different catalysts, they're working with different motivations in mind. So- so all of those things are completely separate. Now of course I think that there are lessons each team can learn that might benefit the other. But yeah, we have kind of two different separate thrusts going on.
Paul Orange (33:45):
[inaudible 00:33:45] the crystal ball question is always a really unfair one. But, um, I'm gonna roll the dice anyway. If you look out into the future, what do you see us in maybe 20 to 25 years experiencing in terms of solar energy generation? And just to give you a couple more minutes to think about it, what- what- what my experience is, I see lots of people putting solar energy on their- on their roofs of their houses, right? And- and using that, either feeding it back into the grid or if you've got a big power wall type thing, storing it locally. There are consumer devices. But, you know, my experience personally on those has been, you end up plugging them into the wall to charge them up. You- you- you know, they very rarely generate a sufficient amount of- of energy for what you need. Do you think that we're gonna be seeing in- in that sort of 20, 25 year timescale, consumer-level devices that are- are harnessing solar energy f- to make electricity? Or are they likely to be, you know, a little bit more complex, really more at a- an industrial scale?
Amanda Morris (34:52):
I think right now if we're talking about the next 20 years, I think where we're gonna see it is more the industrial scale. I mean if you looked at it now, so I think it was in 2018 when an Arizona company First Solar actually won a bid to build a solar battery plant in Arizona. Um, and they won that because solar coupled to batteries was actually less expensive to build a new plant than to build a new natural gas plant. And so, I think from the perspective of new things being built, they're gonna be built with solar energy and batteries in mind. And I think that makes a lot of sense because one of the issues with consumers putting solar panels on their house, and I should say this even though we're about to get solar panels put on our house, uh, the problem with that is feeding it back into the grid. The grid can't (laughs) can't, and is not meant, or at least, you know, our United States grid, is not meant to take energy back from those solar panels. And oftentimes we're just over taxing these very old systems. That's not a solution that we currently are able to do well with. So we have rolling blackouts and all of this stuff.
Amanda Morris (35:59):
It makes much more sense, I think, industrially to then build solar farms that are coupled to batteries that when energy demand is low, we can just be charging the batteries, and when energy demand is high, we can be pumping it out to- to- to homes. And so, I- you know, I think that's- that's what we're gonna see in the next, uh, 20 years.
Paul Orange (36:21):
Mm-hmm (affirmative).
Amanda Morris (36:21):
I- I can dream and hope that you're gonna see an artificial photosynthetic system. But in the reality of- of what I actually think is possible and how slow we move in terms of technology, not necessarily development, but folding into actual society. Right?
Paul Orange (36:35):
Mm-hmm (affirmative).
Amanda Morris (36:36):
So- so how slow we move to actually fold it into society, I- I don't see that happening in- in the next 20 years.
Paul Orange (36:43):
I think your experience in the US with the grid is pretty universal, you know? When they were originally designed, power was supposed to flow one way. So a little bit short term, you know, what's your, you know, research focus looking like? Even for the next year or two. Any particular topics you're interested in- in digging into or, you know, where's your- your research taking things?
Amanda Morris (37:05):
Uh, on the- the the water oxidation side I- I mentioned that we now are able to show that we made these catalysts stable.
Paul Orange (37:11):
Mm-hmm (affirmative).
Amanda Morris (37:11):
Um, which is great. But those catalysts still operate at very high energy requirements. And so it turns out that the power that I get from the solar photons that I'm harvesting is not actually strong enough to couple to those catalysts. So like I've got a really great stable catalyst, but I can't actually interface it with the solar photon generating system. And so, you know, in- in that area, our next thrust is kind of really understanding w- we need to manipulate the catalyst to move its energetics, we need to manipulate the- the solar harvesting center to- to try and match those and bring those together. So that's really where our focus on that side is.
Amanda Morris (37:45):
On- on the CO2 reduction side, I mean we're still working on the same problem that many people are, which is the selectivity thing. So- so how do we get to the product that we want? And how do we get to more valuable products? There are a lot of catalysts out there that can make carbon monoxide.
Paul Orange (37:58):
Right.
Amanda Morris (37:58):
That has value because we can make it in a mixture of carbon monoxide and hydrogen, you can then put it into known industrial processes to make higher value chemicals. But wouldn't it be better if I could just make those higher value chemicals from step one? Instead of having to put it into a separate process? And so we're trying to understand how to do that. And then new- I shouldn't say it's new, but relatively new idea, which makes complete sense when you think about it, is that each step of CO2 reduction is very hard. And oftentimes what we're asking a catalyst to do is all of them. Can you do step one through 20 really well? One thing, right? I don't do 20 things really well. I probably do about five things really well. And you probably do five different things really well. And so doesn't it make more sense to bring me doing five things really well and you doing five things really well together to work on a process? Because ultimately the- the end product will be better. And so what people are developing now are things called cascade systems, where one catalyst does a part of it really well, and that's great, and then it interfaces with another catalyst that does the other parts really well, if that kinda makes sense?
Amanda Morris (39:03):
And so sometimes this can be two catalysts, it can be three things, right? You can bring these together. That's a challenge, because as I mentioned, some catalysts don't work under the same conditions as other catalysts. So now you're trying to create things that don't wanna work together in the same system to work together. And so that's a whole new thing. But ultimately it may end up being better than trying to make one single catalyst do everything. And so that's where we're going on kind of the- the CO2 reduction side.
Paul Orange (39:29):
Amanda, I know from what you've said earlier, you're incredibly busy preparing for some stuff that's coming down. So I think that's a really, uh, good point for us to wrap up. Before we do, if people wanna check out your research or your group, is there anywhere particular they should look to find you?
Amanda Morris (39:45):
Oh, they can head to my website. So I- I probably should know what my website address is, but I don't actually. Um-
Paul Orange (39:51):
Cool, we will- we'll put a link to it in the show notes (laughs).
Amanda Morris (39:53):
Yeah. But you can- you can go to my website. I have kind of a description and our research on there. And of course it has contact information, so if you have any questions, feel free to reach out.
Paul Orange (40:02):
Great. Well, Amanda thank you very, very much for your time today. Um, and just really good luck. I mean this feels like super important research and you know, the- the benefits I think are high on everyone's mind at the moment. So I think, uh, yeah we all hope that you're very successful and, you know, moving a lot quicker than you're anticipating. So, uh, thanks for joining us today.
Amanda Morris (40:22):
No problem. Thanks for having me.
Paul Orange (40:25):
Okay, well, I have to finish the show up today by once again thanking Amanda. She is exceptionally busy, so it was a real privilege to get the time that we had. Uh, I got a lot from that discussion, I- I hope you all did as well. We'll be back again in a couple months time with another great guest. And as always, if there's anybody you feel we should have on the show, please drop us a line. Uh, and even if that's you, we don't mind a bit of shameless self-promotion. But until next show, everybody stay well, look after each other, and, uh, catch you next time on the Modern Chemistry podcast.
Paul Orange (41:07):
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