Oxide-derived Silver Nanowires for CO2 Electrocatalytic Reduction to CO

Abstract

Silver electrocatalysts offer the possibility to produce CO by converting CO2, enabling the use of a greenhouse gas as chemical building block. Compared to nanoparticles, silver nanowires show an enhanced selectivity towards CO. Recent publications proved that oxide-derived electrocatalysts can exhibit better catalytic performance than the pristine metal phase, but oxide-derived silver nanowires have not been investigated. In this work, we report for the first time the electrocatalytic properties of silver nanowires, synthesized via the polyol method, and pretreated by electrochemical oxidation in basic electrolyte. By increasing the oxidation potential, both the percentage of AgxO and the surface roughness of the catalyst were progressively increased. The most oxidized sample showed a remarkably improved CO selectivity (−294.2 mA m−2Ag), producing a 3.3-fold larger CO partial current density than the pristine sample (−89.4 mA m−2Ag), normalized by electrochemically active silver surface area. This work demonstrates the beneficial effect of the controlled oxidation treatment even on highly selective nanostructures such as silver nanowires.