Integrated catalyst-electrodes for the production of solar fuels

Abstract

Immobilization of selective catalysts for fuel- forming reactions on (photo) electrode surfaces is an appealing route to structures for the generation of renewable fuel. Our recent work has focused on immobilization of mol. catalysts on graphitic carbon electrode surfaces via noncovalent interactions. The general approach relies on a pyrene- appended bipyridyl ligand (P) that serves as the linker between the catalysts and the surface. With this method, proton redn. to dihydrogen was catalyzed with an immobilized rhodium complex, [Cp*Rh(P) Cl] Cl, and CO_2 redn. to CO was catalyzed with a rhenium complex, Re(P) (CO)_3Cl. Spectroscopic studies of the [Cp*Rh] - and [Re(CO)_3] - functionalized electrodes are providing new insights into the activity of these assemblies. Catalysis continues over the timescale of hours, and in the case of hydrogen evolution, with estd. turnover frequency near 1 per s. We are also now extending work to earth- abundant systems, and have prepd. Mn(P) (CO)_3Br as a candidate CO_2 - redn. catalyst. Immobilization results in electroactive material, and electrocatalytic CO prodn. has been measured. Recent results will be presented, including spectroscopic characterization, electrochem. stability, and electrocatalytic CO_2 redn. with these catalysts.