Quantum-Dot-Derived Catalysts for CO2 Reduction Reaction

Abstract

Defect sites are often proposed as key active sites in the design of catalysts. A promising strategy for improving activity is to achieve a high density of homogeneously dispersed atomic defects; however, this is seldom accomplished in metals. We hypothesize that vacancy-rich catalysts could be obtained through the synthesis of quantum dots (QDs) and their electrochemical reduction during the CO2 reduction reaction (CO2RR). Here, we report that QD-derived catalysts (QDDCs) with up to 20 vol % vacancies achieve record current densities of 16, 19, and 25 mAcm−2 with high faradic efficiencies in the electrosynthesis of formate, carbon monoxide, and ethylene at low potentials of –0.2, –0.3, and –0.9 V versus reversible hydrogen electrode (RHE), respectively. The materials are stable after 80 hr of CO2RR. These CO2RR performances in aqueous solution surpass those of previously reported catalysts by 2×. Together, X-ray absorption spectroscopy and computational studies reveal that the vacancies produce a local atomic and electronic structure that enhances CO2RR.