The modern-day alchemists in Alexander Katz's UC Berkeley laboratory are concentrating on the engineering of catalysts—those chemical substances that, like enzymes in plants, trigger biological transformations necessary in the conversion of biomass to fuel. It's a tricky balancing act of organic and inorganic substances, but an essential one if the biofuel process is going to be economically viable. "People have used a variety of approaches for processing biomass to biofuel," said chemical engineer Katz, principal investigator for the EBI project, "Enzyme-Inspired Catalysts for Enhancing Biofuels Production". "For example, they will use heat to create a thermal reaction, but that's typically not very selective. You will sometimes lose one-half or more of the product to waste material. You can't afford to throw away so much fuel." What is needed, Katz said, is a system that induces transformations, like hydrolysis and depolymerization, rapidly and with minimal loss of biomass. Enzymes perform these functions expertly in nature, but "no one really knows exactly how enzymes work the way they do," he said. "Biocatalysts can do these transformations with high selectivity. We are looking at the mechanisms being postulated, to see if we can develop synthetic systems with improved selectivity and efficiency." Right now, the Katz team is focused on "bifunctional catalysis," a procedure that involves the use of both acids and bases in a delicate push-pull of electron density. The idea is to develop a catalyst that will break the carbon and oxygen bonds in cellulose and lead to their reassembly as fermentable sugars in the fuel production process. "The organization between acid and base needs to be just right, and the requirements are very stringent—a shift of plus or minus one angstrom (the size of an atom) can sometimes make a difference," said Katz. Combine that with the variations presented by biomass feedstocks, and the challenge of making effective synthetic catalysts becomes intimidating indeed. Their novel approach to the problem involves the use of cellulosic organic and inorganic hybrid materials, creating composites that enable "cooperative catalysis" like natural enzyme mechanisms employ. The role of the biomimetic aspect is to offer new chemically selective conversion systems. Katz's group has already had success in building prototypes of these materials that push these approaches into the realm of emerging and promising methods for biomass pretreatment and cellulose dissolution, depolymerization, and deoxygenation. It's new territory for Berkeley's chemical engineers, but early results show promise on model systems. Katz, research specialist Andrew Solovyov, and postdocs Tatiana Luts, Oz Gazit and Alexandre Charmot are convinced that catalysts-bydesign will enhance biofuels production in unprecedented and innovative ways.