Noncovalent immobilization of electrocatalysts for fuel production on carbon electrodes

Abstract

Assembling systems for the conversion of solar light energy into chem. fuels (i.e., artificial photosynthesis) requires the development of strategies for functionalization of electrode surfaces with catalysts. We have demonstrated that mol. catalysts for fuel-forming reactions can be immobilized on graphitic carbon electrode surfaces via noncovalent interactions. Our general approach relies on a pyrene-appended bipyridine ligand that serves as the linker between the catalysts and the surface. Immobilization of a rhodium proton-redn. catalyst and a rhenium CO_2-redn. catalyst afford electrocatalytically active assemblies. XPS and electrochem. studies confirm catalyst immobilization. Redn. of the rhodium system in the presence of p-toluenesulfonic acid results in catalytic H_2 prodn., while redn. of the rhenium system in the presence of CO_2 results in catalytic CO prodn.