Amino-Induced CO Spillover to Boost the Electrochemical Reduction Activity of CdS for CO Production.

A considerable challenge in CO reduction reaction (CORR) to produce high-value-added chemicals comes from the adsorption and activation of CO to form intermediates. Herein, an amino-induced spillover strategy aimed at significantly enhancing the CO adsorption and activation capabilities of CdS supported on N-doped mesoporous hollow carbon sphere (NH-CdS/NMHCS) for highly efficient CORR is presented. The prepared NH-CdS/NMHCS exhibits a high CO Faradaic efficiency (FE) exceeding 90% from -0.8 to -1.1 V versus reversible hydrogen electrode (RHE) with the highest FE of 95% at -0.9 V versus RHE in H cell. Additional experimental and theoretical investigations demonstrate that the alkaline -NH group functions as a potent trapping site, effectively adsorbing the acidic CO, and subsequently triggering CO spillover to CdS. The amino modification-induced CO spillover, combined with electron redistribution between CdS and NMHCS, not only readily achieves the spontaneous activation of CO to COOH but also greatly reduces the energy required for the conversion of COOH to CO intermediate, thus endowing NH-CdS/NMHCS with significantly improved reaction kinetics and reduced overpotential for CO-to-CO conversion. It is believed that this research can provide valuable insights into the development of electrocatalysts with superior CO adsorption and activation capabilities for CORR application.