2
Government, Industry, and Academic Perspectives on Bioinspired Chemistry for Energy

During three different sessions of the workshop, government, industry, and academic representatives presented perspectives on bioinspired chemistry for energy. Representing the federal government were Eric Rohlfing of the U.S. Department of Energy’s (DOE’s) Office of Basic Energy Sciences; Michael Clarke of the National Science Foundation’s (NSF’s) Chemistry Division; Judy Raper of NSF’s Division of Chemical, Bioengineering, Environmental and Transport Systems; and Peter C. Preusch of the National Institutes of Health’s (NIH’s) Pharmacology, Physiology, and Biological Chemistry Division. The industry perspective was provided by Henry Bryndza of DuPont, Brent Erickson of the Biotechnology Industry Organization, and Magdalena Ramirez of British Petroleum (BP). Daniel Nocera from the Massachusetts Institute of Technology discussed the issue from an academic point of view.

GOVERNMENT PERSPECTIVE

Eric Rohlfing, DOE, discussed the bioinspired chemistry for energy work being done in the agency’s Office of Basic Energy Sciences (BES). The office funds basic research that will lead to revolutionary discoveries to address energy issues. He categorized the work being done into three broad areas, although he did not go into detail about the third since it is not in the division he manages. The overall theme of these areas is to learn from nature but also to figure out how to accomplish tasks more quickly.

  1. Learning how to convert sunlight into chemical fuels like nature does, only better.

    • Detailed studies of the molecular mechanism of natural photosynthesis to create artificial systems that mimic some of the remarkable traits of natural ones (i.e., self-assembly, self-regulation, and self-repair) while improving efficiency.

    • Work encompasses light harvesting, exciton transfer, charge separation, redox chemistry and uses all the tools of the modern physical sciences in conjunction with molecular biology and biochemistry.

  1. Learning catalysis tricks from nature.

    • Apply lessons learned from natural enzymes to the design of organometallic complexes and inorganic and hybrid solids that catalyze pathways with unique activity and selectivity.

    • Characterize the structure and dynamics of active sites in enzymes and the correlated motions of secondary and tertiary structures. Measure half-lifetimes of individual steps of electron- and ion-transport during catalytic cycles. Synthesize ligands for metal centers and functionalize inorganic pores to attain enzyme-like activity and selectivity with inorganic-like robustness.

  1. Learning from nature about how to make novel materials.

    • Emphasis on the merger of biological and inorganic systems at the nanoscale.

Rohlfing presented an organizational chart of the Chemical Sciences, Geosciences, and Biosciences Division, which he manages. He pointed out the four programs in the division that are working on bioinspired chemistry for energy: Solar Photochemistry, Photosynthetic Systems, Physical Biosciences, and Catalysis Science. The goal of these programs is to define and understand the structure, biochemical composition, and physical principals of natural photosynthetic energy conversion.

A major research goal of BES is to figure out how photosynthesis works and then design artificial or biohybrid



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2 Government, Industry, and Academic Perspectives on Bioinspired Chemistry for Energy During three different sessions of the workshop, govern- self-assembly, self-regulation, and self-repair) while ment, industry, and academic representatives presented improving efficiency. • Work encompasses light harvesting, exciton perspectives on bioinspired chemistry for energy. Represent- ing the federal government were Eric Rohlfing of the U.S. transfer, charge separation, redox chemistry and uses all Department of Energy’s (DOE’s) Office of Basic Energy Sci- the tools of the modern physical sciences in conjunction ences; Michael Clarke of the National Science Foundation’s with molecular biology and biochemistry. (NSF’s) Chemistry Division; Judy Raper of NSF’s Division 2. Learning catalysis tricks from nature. • Apply lessons learned from natural enzymes to of Chemical, Bioengineering, Environmental and Transport Systems; and Peter C. Preusch of the National Institutes of the design of organometallic complexes and inorganic Health’s (NIH’s) Pharmacology, Physiology, and Biological and hybrid solids that catalyze pathways with unique Chemistry Division. The industry perspective was provided activity and selectivity. • Characterize the structure and dynamics of by Henry Bryndza of DuPont, Brent Erickson of the Bio- technology Industry Organization, and Magdalena Ramirez active sites in enzymes and the correlated motions of of British Petroleum (BP). Daniel Nocera from the Massa- secondary and tertiary structures. Measure half-lifetimes chusetts Institute of Technology discussed the issue from an of individual steps of electron- and ion-transport during academic point of view. catalytic cycles. Synthesize ligands for metal centers and functionalize inorganic pores to attain enzyme-like activity and selectivity with inorganic-like robustness. GOVERNMENT PERSPECTIVE 3. Learning from nature about how to make novel Eric Rohlfing, DOE, discussed the bioinspired chem- materials. • Emphasis on the merger of biological and inor- istry for energy work being done in the agency’s Office of Basic Energy Sciences (BES). The office funds basic ganic systems at the nanoscale. research that will lead to revolutionary discoveries to address energy issues. He categorized the work being done into three Rohlfing presented an organizational chart of the broad areas, although he did not go into detail about the third Chemical Sciences, Geosciences, and Biosciences Divi- since it is not in the division he manages. The overall theme sion, which he manages. He pointed out the four programs of these areas is to learn from nature but also to figure out in the division that are working on bioinspired chemistry how to accomplish tasks more quickly. for energy: Solar Photochemistry, Photosynthetic Systems, Physical Biosciences, and Catalysis Science. The goal of 1. Learning how to convert sunlight into chemical these programs is to define and understand the structure, fuels like nature does, only better. biochemical composition, and physical principals of natural • Detailed studies of the molecular mechanism photosynthetic energy conversion. of natural photosynthesis to create artificial systems that A major research goal of BES is to figure out how mimic some of the remarkable traits of natural ones (i.e., photosynthesis works and then design artificial or biohybrid 

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 BIOINSPIRED CHEMISTRY FOR ENERGY systems that directly produce solar fuels better than plants The third research project presented by Rohlfing looked do to avoid having to use plants. Rohlfing presented three at the intrinsic motions of proteins as they influence cataly- examples of research sponsored by BES that demonstrate sis and enzymes. Characterizing the intrinsic motions of how chemistry relates to dynamics and change. enzymes is necessary to fully understand how they work as First, the Fenna-Matthews-Olson, or FMO, complex is catalysts. As powerful as structure-function relationships are, a bacteria-chlorophyll complex that acts as a photosynthetic the motion of these proteins is intimately connected with system (Figure 2.1). It is a conduction device for transporting their catalytic activity and cannot be viewed as static struc- the electrical energy when harvesting light. Researchers are tures. This realization, asserted Rohlfing, could revolutionize trying to determine how energy is transferred along the set of and accelerate approaches to biocatalyst design or directed chlorophylls. Is it by energy hopping or is there some more evolution, and could alter understanding of the relations complex physical process? Coherent spectroscopy based on between protein structure and catalytic function. a femtosecond photon-echo technique in the visible region of The next speaker was Michael Clarke of NSF’s Chem- the spectrum was applied to the FMO complex to determine whether there is quantum coherence (quantum beats) in the istry Division. He explained that the NSF funds a broad system. Quantum coherence is important because it helps range of science and that the agency is concerned about avoid kinetic traps, explained Rohlfing. making energy sustainable and solving the carbon dioxide The second example of research being funded by DOE problem. involves a model system, metalloporphyrin, which looks Next he discussed the method that NSF uses to fund the at excited-state evolution using time-resolved X-rays. This scientific research. It has a program that was originally called research sets the groundwork for future research that will be the Chemical Bonding Centers but is now morphing into conducted on much shorter time scales than the femtosecond Centers for Chemical Innovation, which makes a number of domain. relatively small awards, around $500,000, to fund groups of FIGURE 2.1 Model of the photosynthetic apparatus (Fenna-Matthews-Olson complex) in Chlorobium tepidum. SOURCE: Donald A. Bryant, The Pennsylvania State University, and Dr. Niels-Ulrik Frigaard, University of Copenhagen. 2-1.eps bitmap image

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 GOVERNMENT, INDUSTRY, AND ACADEMIC PERSPECTIVES ON BIOINSPIRED CHEMISTRY FOR ENERGY scientists who collaborate in addressing a major chemistry is fast charge recombination following photoinduced charge problem. For example, Harry Gray, Kitt Cummins, Nate transfer. This research has succeeded in reducing the recom- Louis, Dan Nocera, and others are working on a project bination rate. • Francis D’Souza, Wichita State University: This involving the direct conversion of sunlight into fuel. They are in the initial stages of the program and have received research is focused on using assembled nanosystems to about $500,000 so far. After several years, the research separate charges and facilitate transfer, and involves an teams can apply for funding of several million dollars per interdisciplinary team of researchers (Figure 2.2). year. Other similar research projects being funded by NSF Finding a way to organize supermolecular structures in (detailed below) focus on carbon dioxide, photochemical various ways using weak bonds, hydrogen bonds, and physics of charge separation, and finding a way to organize covalent bonds supermolecular structures in various ways using weak bonds, • Dan Reger, University of South Carolina: Using hydrogen bonds, and covalent bonds. water to organize organic molecules into a nanostructure. • Clarke said that finding a way to organize super- Carbon dioxide • Marcetta Darensbourg, Texas A&M University: molecular structures needs to be done in order to affect Looking at carbon-carbon coupling reactions as mediated charge transfers. Forming fuels are synthesized by using by transition metals. The nickel sites serve as the catalyst. all of the types of bonding that chemists have available to • Geoffrey Coates, Cornell University: Using a them to bring together the various components in organized solid-state catalyst to incorporate carbon dioxide into structures, noted Clarke. polycarbonates. • Donald Darensbourg, Texas A&M University: Pio- Judy Raper of NSF’s Division of Chemical, Bio- neered the use of metal catalysts for converting the nontoxic, engineering, Environmental and Transport Systems explained inexpensive carbon dioxide and three-membered cyclic how NSF takes a broad view of bioinspired chemistry. Some ethers (epoxides) to thermoplastics, which are environmen- of the main areas that NSF focuses on are: tally friendly and productively use greenhouse gas emissions. • Bioinspired nanocatalysis for energy production He is also working on developing effective nontoxic metal catalysts for producing a biodegradable polycarbonate from that involves using starch (corn) or cellulose (wood) to pro- either trimethylene carbonate or trimethylene oxide and duce renewable fuels and chemicals. • Bioinspired hydrogen production. carbon dioxide. • Janie Louie, University of Utah: Using platinum • Production of liquid biofuels (both ethanol and and nickel catalysts that allow carbon dioxide to be used as alkanes). • Microbial fuel cells. a starting material for organic synthesis. Photochemical physics of charge separation Raper explained that NSF programs support the follow- • Dmitry Matyushov, Arizona State University: Using ing bioinspired chemistry for energy research under the a ferroelectric medium to facilitate charge transfer since the National Biofuels Action Plan: metabolic engineering, plant main cause of inefficiency of current artificial photosynthesis genome research, catalysis and biocatalysis, biochemical FIGURE 2.2 Supramolecular nanostructures for light driven energy and electron transfer. This research is focused on rational design and study of self-assembled porphyrin, fullerene, and carbon nanotube bearing supramolecular complexes and nanostructures. SOURCE: Presented by Michael Clarke, National Science Foundation; used with permission from Francis D’Souza, Wichita State University.

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0 BIOINSPIRED CHEMISTRY FOR ENERGY Peter C. Preusch of the Pharmacology, Physiology, and and biomass engineering, biotechnology, energy for sustain- ability, environmental sustainability, and organic and macro- Biological Chemistry Division of the National Institute of molecular chemistry. She highlighted some of the currently General Medical Sciences at the NIH discussed the agency’s funded NSF projects. mission and how bioinspired chemistry for energy fits into In the area of bioinspired catalysis, Raper mentioned the it. The mission of NIH is to pursue fundamental knowledge work of a few researchers. Dennis Miller and James Jackson about the nature and behavior of living systems and the appli- at Michigan State are exploring taking starch or cellulose, cation of that knowledge to extend healthy life and reduce extracting the carbohydrate, and fermenting it to organic acid the burdens of illness and disability. That mission, asserted and glycerols. Robert Davis at the University of Virginia is Preusch, has allowed interesting dual-use science to be looking at gold nanoparticles as catalysts for the conversion supported that is relevant to both basic energy research and of glycerol to glyceric acid. human health. NIH has a large budget but nothing earmarked Raper also highlighted work in the area of bioinspired for research in this area. The National Institute of General hydrogen production and microbial fuel cells. David Dixon Medical Sciences is one of the largest supporters of chemical at the University of Alabama is studying photocatalytic sciences research in the nation, said Preusch. production of hydrogen. Bruce Logan of Pennsylvania State The bioinspired chemistry research that has been sup- University is looking at hydrogen production by fermenta- ported by NIH falls into two categories: (1) chemical models tion of waste water (as well microbial fuel cells for energy of biological processes for the purpose of better understand- production; Figure 2.3). Dianne Ahmann at the Colorado ing those biological processes and (2) using chemistry that is School of Mines is using Fe-hydrogenase to produce com- related to biology or using biological catalysts to accomplish mercial algal hydrogen. Lars Angenent of Washington Uni- chemical processes at a scale that is industrially significant. versity Nonfermentable products in wastewater are being Preusch provided examples of investigator-initiated used to produce electricity in microbial fuel cells. grant-based projects funded by NIH that address funda- NSF also supports production of liquid biofuels. James mental physical processes and reactions of elements that are Dumesic at the University of Wisconsin is looking at green important in both global energy cycles and human health. gasoline, which involves using inorganic catalysts to make Note that NIH has not solicited proposals in this area, but alkanes, jet fuels, and hydrogen. Dumesic is breaking up cel- has supported a considerable amount of research that reflects lulose to make aqueous phase reforming through syngas for investigator-initiated ideas in the field. alkane products, hexane, and through hydroxymethyfurfural • Energy transfer: How light energy is captured, to make jet fuels or polymers. Ramon Gonzales at Rice University is exploring anaerobic fermentation of glycerol transmitted from an initial absorbing molecule through a in E.coli for biofuels production. series of intermediate molecules to a site at which that energy is captured in the form of electron-proton separation across a membrane. • Electron transfer: Basic to the function of the respi- ratory chains of mitochondria and bacterial pathogens. • Oxygen activation: Work on mimics of cytohrome P450 to understand how they function and use catalysts in order to activate molecules for oxygen insertion and to acti- vate oxygen. • Oxygen reduction: Models have been created for cytochrome oxidase, which have provided insights into the oxygen activation and reduction mechanism. • Hydrogen peroxide: Model studies on catalases, per- oxidases, and superoxide dismutases have provided insights into biological protection against oxidative damage. • Hydrogen reduction: Model studies of hydrogenase provide insights relevant to the pathogenic organism Helicobacter pylori and its ability to survive in the gastric mucosa. • Nitrogen oxide production and reduction: Relevant to the production and disposal of nitrogen oxides as signal- ing molecules and biological responses to environmental 2-3.eps FIGURE 2.3 Power Generation with Microbial Fuel Cells. nitrogen oxides. SOURCE: Presentation just 110%—not fullScience Founda- enlarged this of Judy Raper, National width— • Nitrogen reduction: Nitrogenase has been a model tion; used with permission from Bruce Logan, Pennsylvania State so resolution would not suffer system for studying general principles involving electron University.

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 GOVERNMENT, INDUSTRY, AND ACADEMIC PERSPECTIVES ON BIOINSPIRED CHEMISTRY FOR ENERGY transfer, energy coupling, fundamental structures of metal ethanol industries. Offerings under development from bio- complexes, and the chemical control of their assembly. mass feedstocks include improved biomass to energy, crop protection chemicals, and cellulosic ethanol and butanol At the end of his talk, Preusch described the grant appli- technologies coming from biorefineries. cation and award process for regular research grants, confer- Biomass includes a range of materials from simple plant ence grants, and academic research enhancement awards. oils and sugars that can be converted into liquid transporta- tion fuels to cellulose, hemicellulose, and lignocellulose which are successively much harder to address. Bryndza INDUSTRY PERSPECTIVE explained that there are many potential conversion processes Henry Bryndza of DuPont began his presentation by that deliver energy in different ways, ranging from distrib- emphasizing how expansive the subject area of this Bio- uted power or stationary power to liquid transportation fuels. inspired Chemistry for Energy workshop can be, stating, DuPont is working on a number of different conversion “When I think about ‘bioinspired,’ it means everything from processes and trying to identify the most efficient ones. The biomimetics to superior process technology for bioprocesses, cellulosic ethanol program is a consortium effort involving through integrated science approach, to even the production other companies, government laboratories, and academia. of chemicals and materials that are enabled by an emerging The project is looking at a variety of chemical and biological infrastructure in renewably available feedstocks. Similarly, technologies to convert biomass into useful products ranging when you’re talking about ‘energy,’ it’s not only energy from fuels to chemicals and materials. DuPont thinks that the production in terms of conventional sources that are in wide- variation in biomass feedstocks will require an integration of spread use today but also so-called alternative or renewable sciences and multiple technologies. energies.” He also said that recycling and use minimization Bryndza believes that integration is important to finding should be considered in the overall energy picture. the best solution to the world’s energy crisis. If scientists Bryndza believes that a tipping point has been reached approach energy problems from either a biological perspec- in the drive for alternative energy sources and that they offer tive or a chemical perspective, asserted Bryndza, alternative significant potential for future growth. The success or failure energy technologies will not work economically. He said, of alternative energy sources, claimed Bryndza, has major “We really need partnerships. . . . We are partnering in implications for the United States as well as for the planet in virtually all of these areas for a couple of reasons. One is terms of political climate, environmental performance, and that we can’t do it all ourselves. The second is that, in some economic health. He believes it is unlikely that there will be cases, partners bring technology or access to markets that one global solution; rather, he thinks there are going to be we don’t have.” local minima that are dictated, in part, by availability and cost Brent Erickson of the Biotechnology Industry Orga- of technology and its capital intensity. The availability and cost of feedstocks vary by region, and different governments nization (BIO) said his organization is the world’s largest have different subsidies, regulations, incentives, and policies trade association, with over 1,000 member companies in that will also drive the local minima for fast adoption. 33 countries. It represents the gamut of biotechnology from Bryndza explained how DuPont is a science company health care to food and agriculture biotech to industrial and that is heavily dedicated to the energy market and sustain- environmental biotech. According to Erickson, pharmaceu- able growth. He talked about the company’s sustainability tical and agriculture areas are already well developed, so policies that were established in 1989 and updated in 2006. the next wave is fuels, chemicals and manufacturing, bio- By 2010, Bryndza estimated 25 percent of revenues from polymers, chiral intermediates, and products for farm and DuPont’s businesses are expected to be derived from opera- fine chemicals. BIO advocates on Capitol Hill are currently tions using raw materials that are not depleted, and 10 per- trying to gain support from policy makers for biorefinery cent of the company’s energy needs will be derived from development. renewable sources. Erickson provided several reasons why industrial bio- Bryndza then touched on the selection criteria that tech is important for innovation and commercialization: DuPont uses to decide which projects to undertake. Projects • Because process innovation is slowing, the chemi- must be consistent with the corporate vision and sustain- ability principles, unique, multigenerational, consistent cal industry must identify new places to find innovation. • Energy prices and availability of petroleum-based with DuPont competences, have a valid route to market, and DuPont’s stake needs to be large enough to justify the feedstocks are problematic. • The global marketplace is becoming increasingly effort. DuPont is already heavily invested in products, services, competitive. • Industrial biotech is advancing rapidly, providing and research in support of global energy markets as diverse as petrochemicals, fuel cells, photovoltaics, and biofuels. new tools for innovation, cost reduction, and improving The company supplies products to the sugar- and corn-based environmental performance.

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 BIOINSPIRED CHEMISTRY FOR ENERGY • the chemistry is oxygen-based compared to hydro- Industrial biotech represents a broad range of applica- tions, including biobased products, bioenergy, biobased gen in hydrotreatment; • the handling is facilitated by the conditions used; polymers, and national defense. The Department of Defense, • selectivity in biocatalysis involves a specific com- for example, has a program to build mobile biorefineries that recycle kitchen waste. pound, while catalytic hydrotreatment involves a family of Erickson’s vision for the future includes creating a compounds; • their application addresses improvements in product biobased economy in which the basic building blocks for industry and raw materials for energy are derived from quality; • they may minimize pollution and waste; renewable plant sources and are processed using industrial • they simplify the refining process by reducing sepa- biotechnology. According to Erickson, technologies should be developed that go beyond a simple starch-to-ethanol ration and disposal stages; and • they offer economic benefits. platform that exists now. Erickson believes that industrial biotechnology is attrac- tive to business because it can decrease production costs and Ramirez then highlighted some achievements in bio- increase profits, increase the sustainability profile, allow for refining. A wide range of biocatalysts have been discovered broader use of renewable agricultural feedstocks instead of from research at the cellular and subcellular level and have using petroleum, and provide precision catalysis. However, evolved through cloning and engineering of the microbial he thinks industrial biotechnology can also be disruptive catalyst. Catalytic properties have been improved by broad- as it converges with other scientific disciplines because of ening the selectivity of the biocatalyst. A more thermally its shorter research and development cycles. Erickson then stable catalyst has been patented and an attempt has been discussed the importance of partnership among companies, made to integrate those processes into refinery operations. which is detailed in Chapter 5. Ramirez said that catalytic activity has particularly been So how will the biobased economy actually happen? improved for enzymes involved in desulfurization. A large Erickson believes that radically new business models will effort in enzyme isolation and characterization has been appear that challenge traditional companies, but unique made. Although some of the enzymes are known to contain opportunities for the fast movers will be created. Companies metal clusters or metal sites, Ramirez noted that very little that are early adopters of industrial biotech will gain a com- is known about their chemical nature and their catalytic role petitive advantage in the marketplace, said Erickson. in the enzymatic action. She claims that scientists need to What is the market potential? Industrial biotech is understand these issues in order to contribute to technology already 5 percent of global chemical production, and development. Erickson believes it will continue to accelerate rapidly. Other biological processes have also been considered McKinsey and Company estimates that by 2010 industrial for improving refining. Ramirez sees that regulations on biotech could be worth $280 billion. sulfur are becoming tougher and the supply of heavy oil is In conclusion, Erickson stated that, “industrial biotech growing, leading to higher sulfur content in the feedstocks. and biological chemistry are really at the right place at the Therefore, said Ramirez, producing the required cleaner right time with the right tools to make a big difference in our products involves overcoming more difficult challenges. In energy security, our economy, and our environment.” conventional refining the hydrogen needs increase the opera- tional costs, as a result of finding new chemistries for remov- Magdalena Ramirez of BP focused on crude oil refin- ing sulfur. Not much is known about the active site in the ing using biocatalysis and biotechnologies. She addressed biological catalysts or the molecular mechanisms. Ramirez achievements of biorefining and potential interaction of explained that the metabolic pathway of desulfurization is conventional refining and biorefining. There have been well established. The pathway links the intermediate metabo- large investments made in crude oil biorefining over the lites of the reaction, but it is not known how one molecule last 20 years, but that has only reached the pilot-plant is converted into another. Performance relationships that scale. Crude oil refining is complex, said Ramirez, as hydro- are well known in chemistry or in ordinary heterogeneous cracking and hydrotreatment occur at very high temperatures or homogeneous catalysis are not valid in the biocatalytic and pressures. The products of crude oil refining include mechanisms. petroleum gases, naphtha, kerosene, gas oil (diesel oil), Does it make sense to mimic the structural catalyst or lubricating oil, fuel oil, and residue which are made up of a to mimic how they work? Ramirez thinks that scientists variety of molecules rather than a single molecule. need to understand the function rather than the structure According to Ramirez, biocatalytic processes could be of biocatalysts, and that scientists should investigate how useful in crude oil refining because: biocatalysts work rather than what they are. It is important, said Ramirez, to address the selectivity issues and improve • they moderate conditions such as pressure and the performance of a biocatalyst when mimicking ordinary temperature; chemistry. She feels that stability should be addressed

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 GOVERNMENT, INDUSTRY, AND ACADEMIC PERSPECTIVES ON BIOINSPIRED CHEMISTRY FOR ENERGY because biocatalysts are not stable at the conditions that hydrogen, would be placed on one end and an anode on the refineries normally operate and that catalysis should be as other. Reduction would take place and the anode would drive efficient as possible. water oxidation. The process ends up separating catalysis Ramirez expects that biorefining will bring new insights from capture and conversion. into refining, new chemistry, and new processes that are more Nocera listed the main factors that will change for enact- energy efficient and emphasize of product quality. In the end ing solar energy: collaboration will lead to greener solutions for refining. • Cheap and efficient PVs; • Replace noble metal catalysts (for fuel and solar ACADEMIC PERSPECTIVE cells) with inexpensive metals; • New chemistry for water splitting. Daniel Nocera of the Massachusetts Institute of Tech- nology began his presentation by discussing a paper he wrote for the Proceedings of the National Academy of Sciences He noted the need to manage electrons and protons, in 20061 in which he introduced a roadmap for chemistry’s assemble water, and transfer atoms to make solar energy role in the energy problem. The rest of presentation focused efficient with cheap catalysts. His team has developed several on breaking the nearly linear dependence of energy use and new techniques, such as proton-coupled electron transfer carbon (i.e., replacing coal, gas, and oil). Nocera stated that (which he noted as a human health issue). This technique is the world is on an oil curve in terms of depending on carbon related to energy because it is how energy is stored in the for primary-energy use. If coal is going to be used, posed biology realm. Nocera provided some examples of research Nocera, more efficient processes for mining, burning, and being done in this area. One project involves inventing mul- sequestering carbon should be developed. Population, GDP tielectron chemistry with mixed valency in which metals can per capita, and energy intensity determine how much energy be changed by two electrons using ligands (Figure 2.4). will be needed. The main conclusions from Nocera’s presentation Nocera explained that the chemical equation for his were: research is oil = water + light. High-energy bonds, such as • The need for energy is so enormous that conven- carbon-carbon, hydrogen-hydrogen, and oxygen-oxygen, are rearranged to produce a fuel. When they are burned, tional, long-discussed sources will not be enough. • Solar + water has the capacity to meet future energy bonds are rearranged to produce energy. Nocera believes that the best crops to use for biomass conversion in terms of needs. light energy storage are switchgrass, miscanthus, and cyano- — But large expanses of fundamental molecular bacteria. Corn is the crop that is usually mentioned, said science need to be discovered. There are many intriguing Nocera, because of the corn industry’s lobbying effort and problems to study. because conversion of starch to ethanol is well understood. Corn is an energy-intensive crop, requiring a large amount of energy to generate high-energy polymers in sugar and starch versus cellulose and lignin. Switchgrass and miscanthus have hardly any sugar or starch in them; they are made up The one-electron mixed valence Can a two-electron (and four) world defined by Henry Taube chemistry be uncovered with of cellulose and lignin. Therefore, new microbes or thermo- two-electron mixed valency? chemical catalysts for lignin and cellulose conversion need to be discovered, said Nocera. Nocera is concerned about the amount of carbon dioxide reductions reductions oxidations 2e – 1e– here here here in the atmosphere, and he showed a public education video oxidations here that he helped produce. He believes the carbon dioxide problem can be solved with water and light, which involves Ligand-Based 2e– Mixed Metal-Based 2e– Mixed bond rearrangement. Therefore, said Nocera, the only types Valency Valency of energy that will work, from a renewable and sustainable perspective, are biomass, photochemical, and photovoltaic. He sees a problem with biomass in that it is also a food Julien Alan Bachmann source, so biomass could be limited to a minor role in the Heyduk Max Planck UC Irvine energy future. Institute Asst Prof Nocera then discussed how photosynthesis demonstrates Humboldt Fellow a bioinspired design. He suggested setting up a wireless current that is driven by the sun. A cathode, which produces FIGURE 2.4 Three projects demonstrating multielectron chem- istry with mixed valency. 2-4.eps SOURCE: Presented by Daniel Nocera. Lewis, N. S. and D. G. Nocera. 2006. PNAS 103: 15729-15735. 1

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 BIOINSPIRED CHEMISTRY FOR ENERGY — Renewable energy research is not an engineer- platinum. Turner thinks there are too many combinations ing problem. It has to be tackled as a basic science and a better directed approach is needed. Turner also sug- problem. Catalysis and many new modes of reactivity gested that they get theorists involved in the process to help await discovery. understand synthesis and characterization. Nocera agreed • Chemistry is the central science of energy because with Turner’s comment. it involves light capture and conversion with materials and John Sheats of Rider University pointed out that along storage in bonds. • The problem is too important to let our scientific with the increasing need for energy, a population of nine egos get in the way. There needs to be an honest broker (i.e., billion people will need to be fed. He posed the question, objective group of scientists) who can recommend an honest “Can we use biomass for fuel and feed the world when representation of the strategic investment for energy. we’re not currently feeding the world?” Nocera responded with a simple “Yes,” and mentioned that the food dilemma Following Nocera’s presentation, John Turner of is why the problem of biomass conversion needs to move on the National Renewable Energy Laboratory said that the to lignin and cellulose. Nocera stressed using other energy processes that Nocera discussed are missing something in sources besides biomass. He explained that if the majority of the theory that would explain how to make the inorganic the world’s energy needs were addressed by using biomass, materials mimic what has been done with ruthenium and then there would indeed be a problem.