G. Charles Dismukes - Research

Heterogeneous Water Oxidizing Catalysts from Inert Transition Metal Oxide Spinels

mnoxManganese oxides occur naturally as minerals in at least 30 different crystal structures, providing a rigorous test system to explore the significance of atomic positions on the catalytic efficiency of water oxidation. We chose to systematically compare eight synthetic oxide structures containing Mn(III) and Mn(IV) only, with particular emphasis on the five known structural polymorphs of MnO2. We have adapted literature synthesis methods to obtain pure polymorphs and validated their homogeneity and crystallinity by powder X-ray diffraction and both transmission and scanning electron microscopies.

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Molecular Catalysts for Water Oxidation

c3cp55200d s3 hi resThe development of sustainable catalysts that use materials of high natural abundance and long-term stability is a major goal of this project. Our research is closely linked to the discovery of the catalytic CaMn4O5 site for photosynthetic water oxidation. Armed with nature's emerging blueprint for design of a water oxidation enzyme, we are synthesizing bioinspired inorganic complexes and materials for use in hybrid photoelectrochemical cells as water splitting catalysts. Our proposed mechanism for photosynthetic water oxidation serves as the guiding principle for catalyst design.

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