COORDINATION CHEMISTRY IN ELECTROCATALYSIS

Superior electrocatalysts for the reduction of O2 by four-electrons in one step have been prepared by coordinating ammine complexes of Ru(II ) to the pyridine ligand sites in cobalt tetrakis(4-pyridyl) porphyrin . At least three coordinated Ru(II) centers appear to be required to o btain the four-electron reduction. When fac-Ru(NH3)3(OH2)3(2+) was use d to ruthenate the porphyrin, a network structure was obtained in whic h both terminal and bridging ruthenium centers were present.