A New Family of Catalysts for Production of Solar Fuels

Nature uses a variety of transition-metal containing, cluster-based cofactors to catalyze water oxidation, carbon dioxide reduction, and hydrogen evolution. Efforts to mimic Nature by constructing artificial catalytic clusters are often complicated either by catalyst aggregation and inactivation, or poor catalytic activity due to blocking of catylst active-sites by ligands needed for cluster stabilization or immobilization. We have developed a route to catalytic clusters of well-defined and pre-determined size and composition that is based on deploying atomic layer deposition on electrode-supported arrays of metalloporphyrins, or within appropriately designed, mesoporous metal-organic framework materials. This approach avoids the complications of both catalyst aggregation and ligand inactivation, while setting the stage for systematic, hypothesis-driven investigations of catalyst size/activity and composition/activity relationships.

Our focus thus far has been chiefly on transition-metal oxides and transition-metal sulfides. This talk will present the general approach to catalyst synthesis, as well as some representative findings for water oxidation,water reduction, or CO₂ reduction.