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 CO 2 into formate/formic acid. To control the nanoporous structure of catalysts, we fabricate nanoporous bismuth (Na 3 CA-NPB) by a top-down sodium citrate-modified dealloying approach for improving CO 2 RR. The Na 3 CA-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 Na 3 CA-NPB is attributed to the irregular interpenetrating kink-like nanoporous network in the Na 3 CA-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 CO 2 RR.