Electrocatalytic Rate Alignment Enhances Syngas Generation

Electrocatalytically generating synthesis gas (syngas, CO + H-2) from aqueous CO2 requires balancing the relative rates of CO and H-2 generation such that the needed range of desired syngas compositions can be achieved. By purposely integrating two distinct catalytic materials, one for H-2 generation and one for COgeneration, we deliberately aligned the rates of these two reactions, thereby enhancing syngas tunability as a function of potential. A modular synthetic approach enabled the systematic surface decoration of Au nanostructured electrocatalysts with a series of 3d transition metals, Co, Ni, and Fe, which augmented the selective CO generation of the Au substrate with rapid H-2 generation. The resulting rate-aligned electrocatalyst generates-in contrast with the non-rate-aligned control-a wide range of desirable syngas compositions over a 200 mV range, all at current densities greater than 50 mA/cm(2).