Bio-inspired Solar Light Driven Hydrogen Production

Energy is one of the most important issues of the twenty-first century, because our future supply is currently threatened by progressively decreasing fossil fuel reserves, political instability and environmental problems resulting in pollution and global warming. Renewable hydrogen, H2, is widely considered as a potential future fuel, but its cheap and efficient production is still a major unresolved practical issue. The sun provides our planet with a continuous flow of electromagnetic and carbon-free energy and it is the only energy source, which is capable of sustaining human kind's long-term energy demand. The aim of this EPSRC-funded project is the development of an efficient bio-inspired H2 production catalyst from abundant and inexpensive raw materials and its coupling to light-harvesting complexes to capture energy provided by the sun to power H2 production from water - the storage of solar energy in the chemical bond of H2.Selective and economical chemical catalysts are needed for the central chemical interconversion of energy, water and H2 if there is to be a real prospect of promoting H2 as a sustainable fuel. Commonly employed precious metal catalysts (e.g. platinum) cannot be used for H2 production in the post-fossil fuel era, because of (i) limited resources and high cost, (ii) poor reaction selectivity (e.g. energy is wasted on unwanted side-reactions), and (iii) poisoning (catalyst-killing) by trace amounts of common chemicals, e.g. carbon monoxide. Microbial life forms handle the challenging task of H2 production using bio-catalysts (hydrogenases) to drive the selective and reversible production of H2 from water at fast rates under the safe conditions of room temperature and neutral pH. The catalytic reaction centre (active site) of hydrogenases contains an iron or nickel-iron metal centre surrounded typically by cysteine, carbon monoxide and cyanide ligands. Thus, the active site of a hydrogenase is an interesting biological motif to mimic in order to build H2 production catalysts from abundant and inexpensive raw materials. This adventurous work on solar H2 production has the prospect of being a fundamental step towards large-scale water photolysis for a sustainable hydrogen economy. International (France, USA) and national (Manchester) academic as well as industrial (Evonik Industries) collaborators with expertise in enzyme biology, spectroscopy, solar cells, nanoparticles, and neutron diffraction will support this project under my guidance. In addition, this work on bio-inspired/biomimetic H2 production catalysts will also deal with wastewater treatment, the synthesis of fine chemicals, and might give us insight into how living organisms convert water into H2 on a molecular level, and reveal how the reverse reaction works: the generation of energy from H2, which is important for fuel cell applications.