Boron Phosphide Nanotubes for Electrocatalytic CO Reduction to Multicarbon Products.

Developing an efficient catalyst that can reduce CO to economically viable products provides a pathway to achieve carbon neutrality. For this purpose, we introduce and characterize boron phosphide nanotubes, a class of materials that allow one to reach a goal without costly and toxic metal atoms. The tubular configuration imparts a confining effect, facilitating CO adsorption and catalytic reduction into ethanol. By calculating the transition state conditions under different charging and using grand canonical potential kinetics, we establish the transition state energy barriers in the system at different electrochemical potentials. We further elucidate the kinetics and mechanism of the entire reaction process at the microkinetics level and predict the onset potential to be -0.30 V with the Tafel slope of 93.69 mV/dec. Finally, we demonstrate control over concentrations of the products and intermediate species by the choice of pH and the applied potential. The characterized material class and established chemical mechanisms guide design of electrocatalysts for producing multicarbon products.