Breaking Scaling Relations for Highly Efficient Electroreduction of CO2 to CO on Atomically Dispersed Heteronuclear Dual-Atom Catalyst

Abstract

Conversion of CO2 into value-added products by electrocatalysis provides a promising way to mitigate energy and environmental problems. However, it is greatly limited by the scaling relationship between the adsorption strength of intermediates. Herein, Mn and Ni single-atom catalysts, homonuclear dual-atom catalysts (DACs), and heteronuclear DACs are synthesized. Aberration-corrected annular dark-field scanning transmission electron microscopy (ADF-STEM) and X-ray absorption spectroscopy characterization uncovered the existence of the Mn─Ni pair in Mn─Ni DAC. X-ray photoelectron spectroscopy and X-ray absorption near-edge spectroscopy reveal that Mn donated electrons to Ni atoms in Mn─Ni DAC. Consequently, Mn─Ni DAC displays the highest CO Faradaic efficiency of 98.7% at −0.7 V versus reversible hydrogen electrode (vs RHE) with CO partial current density of 16.8 mA cm−2. Density functional theory calculations disclose that the scaling relationship between the binding strength of intermediates is broken, resulting in superior performance for ECR to CO over Mn─Ni─NC catalyst.