" Hydrogen as a fuel in biology: from the mechanism of hydrogenase enzymes to hydrogenations in biotechnology"

Humanity is still some way off realising the promise of a sustainable energy economy in which clean production of hydrogen gas from water is driven by renewable electricity sources, and hydrogen gas is used to re-generate electricity on demand with water as the only waste. Among the barriers to placing hydrogen as a key component of a sustainable energy economy is a chemical catalysis challenge: the catalysts used to speed up splitting of hydrogen are still based on costly, rare metals, mainly platinum. This is also true in the chemicals industry where catalysts based on precious metals including platinum, palladium and rhodium are needed to split hydrogen gas and add the hydrogen atoms across chemical bonds to hydrogenate unsaturated molecules into valuable chemical products. In contrast, hydrogenase enzymes, found in a wide range of micro-organisms, are impressive in their ability to extract energy from hydrogen gas, or to produce hydrogen, at organometallic catalytic centres built from the common metals, iron and nickel. There is much we can learn from nature.

We have developed a suite of experimental approaches for studying hydrogenase enzymes in which we use electrochemistry to control their catalysis while simultaneously making spectroscopic and structural measurements. These are allowing us to piece together the mechanism of hydrogenases. This work has also led us to develop biotechnologies which exploit hydrogenase enzymes for biocatalytic hydrogenation in organic synthesis, opening up ‘greener’ routes to utilising enzymes in chemical manufacturing.

Catalysis challenges also pose barriers to many other areas of sustainable energy chemistry, ranging from low-temperature synthesis of ammonia as a hydrogen storage agent, to the conversion of carbon dioxide into valuable chemical building blocks. In these areas too, there is much to be learnt from biological catalysis, and we are extending our studies to other areas of bio-inorganic chemistry.

Speaker Bio

Professor Kylie A. Vincent is a Professor of Inorganic Chemistry, and Fellow of Jesus College Oxford.