Highly active coral-like porous silver for electrochemical reduction of CO2 to CO

Abstract

It is widely recognized that metal-based catalytic materials having a porous structure provides a great potential for electrochemical CO2 reduction. In this study, we prepared coral-like porous Ag (CP-Ag) using the electrodeposition approach at various deposition potentials at -0.9 (CP-Ag-0.9), -1.3 (CP-Ag-1.3), and -1.7 V (CP-Ag-1.7), respectively. Among them, CP-Ag-1.3 was revealed to possess the most enhanced CDRR activity and selectivity. The CO partial current density and the faradaic efficiency of CP-Ag-1.3 was 5.3 mA cm−2 and 96.38 %, respectively, which is a substantially high performance surpassingly compared to even the polycrystalline Au known as the most active materials for CO2 reduction. The distinctive CO2 reduction performance of CP-Ag-1.3 resulted from a large surface area, high index facets of the curved surfaces, and an extremely decreased charge transfer resistance. In addition, CP-Ag-1.3 showed an excellent durability without any morphology change in constant current application test for 24 h. The prepared catalysts are capable of enhancing the performance of Ag-based catalysts for the practical application by preparing with cost-effective material.