A series of heterobimetallic complexes containing 3-center,2-electron Au-H-Cu bonds have been prepared from addition of a parent gold hydride to a bent d10 copper(I) fragment. These highly unusual heterobimetallic complexes represent a missing link in the widely investigated series of neutral and cationic coinage metal hydride complexes containing Cu-H-Cu and M-H-M+ moieties (M = Cu, Ag). The well-defined heterobimetallic hydride complexes act as pre-catalysts for the conversion of CO2 to HCO2Bpin using HBpin as a reductant. The selectivity of the heterobimetallic complexes for the catalytic production of a formate equivalent surpasses that of the parent monomeric group 11 complexes.