Conformal Shell Amorphization of Nanoporous Ag-Bi for Efficient Formate Generation.

Simultaneous attainments of high conductivity and superior catalysis are major challenges for amorphous electrocatalysts in carbon dioxide electroreduction at high overpotential. In this study, one protocol is first demonstrated to drive the shell amorphization of nanoporous Ag-Bi (a-NPSB) catalyst with the spatially interconnected ligament during the initial stage of CO2ER. This newborn a-NPSB bestows the outstanding catalysis, evidenced by a Faradaic efficiency of 88.4% for formate production at -1.15 V vs RHE, specific current density of 21.2 mA cm-2, and mass specific current density of 321 mA mg-1. The unique catalysis is considered as the collective contribution of the conductive ligament internally and amorphous Bi2O3 shell with about 3.2 nm thickness externally. Simultaneous obtaining of the conductivity of inner metals and catalytic activity of the amorphous shell will pave a new avenue for designing a robust electrode during electrochemical reaction.