Nanoporous Bismuth Induced by Surfactant-Modified Dealloying for Efficient Electrocatalytic Reduction of CO2 to Formic Acid

Engineering the internal surfaces of 3D nanoporous catalysts is an effective strategy for the efficient electrocatalytic conversion of CO2 into formate/formic acid. To control the nanoporous structure of catalysts, we fabricate nanoporous bismuth (Na3CA-NPB) by a top-down sodium citrate-modified dealloying approach for improving CO2RR. The Na3CA-NPB catalyst exhibits a high-activity selectivity to producing pure formic acid with the maximum Faradaic efficiency above 89% under 100 mA cm–2 and maintains more than 80% Faradaic efficiency over 45 h at the solid-state electrolytic cell. The excellent performance of Na3CA-NPB is attributed to the irregular interpenetrating kink-like nanoporous network in the Na3CA-NPB. Such a structure offers highly active internal exposed crystalline facets enhancing intrinsic activity and the interconnected network facilitating efficient mass transport channels. This work provides a direction to develop high-performance nanoporous catalysts by top-down dealloying for enhancing the CO2RR.