Electrochemical hydrogenation of NO and CO: Differences and similarities from a computational standpoint

Abstract

Electrolyzers can help in restoring the balance to the biogeochemical cycles of carbon and nitrogen while producing valuable chemical compounds. Before that happens on a global scale, various hurdles need to be overcome, some of which are related to the activity and selectivity of the materials used to catalyze electrolysis reactions. For instance, CO and NO are important electrolysis feedstocks and/or reaction intermediates and their hydrogenation is often energetically demanding. Here it is shown how the most favorable hydrogenation product among ∗CHO or ∗COH, and ∗NHO or ∗NOH on late transition metals can be ascertained by classification methods based on adsorption-energy scaling relations and “catalytic matrices”. In particular, late transition metals can be split into weak-binding and strong-binding and there is a noble-nonnoble energy gap between them. Such a simple categorization helps outline the metals and facets that selectively favor the making of O–H, C–H and N–H bonds.