Abstract
The lack of efficient catalysts prevents the electrocatalytic reduction of carbon dioxide from contributing to the pressing target of a carbon-neutral economy. Indium-modified copper nitride was identified as a stable electrocatalyst selective toward CO. In(2) O(3) /Cu(3) N showed a Faradaic efficiency of 80 % at 0.5 V overpotential for at least 50 h, in stark contrast to the very limited stability of the benchmark In(2) O(3) /Cu(2) O. Microfabricated systems allowed to correlate activity with highly stable interfaces in indium-modified copper nitride. In contrast, fast diffusion of indium resulted in rapidly evolving interfaces in the case of the system based on oxide-derived Cu. A metastable nitrogen species observed by spectroscopic means was proposed as the underlying cause leading to the unchanging interfaces. This work reveals the stabilizing properties of nitride-derived copper toward high-performance multicomponent catalysts.