Copper decorated with nanoporous gold by galvanic displacement acts as an efficient electrocatalyst for the electrochemical reduction of CO2

Abstract

The reduction of carbon dioxide (CO₂) is recognized as a key component in the synthesis of renewable carbon-containing fuels. Herein, we report on nanoporous gold (NPAu) decorated with copper atoms for the efficient electrochemical reduction of CO₂. A facile and green galvanic displacement technique was developed to incorporate Cu onto the surface of the nanoporous gold-zinc (NPAuZn) electrode. The effect of zinc on the morphology and electrochemical performance of the formed NPAuCu electrodes for CO₂ reduction was systematically investigated. The NPAuCu electrode exhibited 16.9 and 2.86 times higher current density than those of polycrystalline gold and NPAuZn at −0.60 V (vs. RHE) in a 0.1 M CO₂-saturated NaHCO₃ solution, respectively. A far higher faradaic efficiency was achieved at the NPAuCu electrode for the electrochemical reduction of CO₂ to CO, CH₄ and HCOOH. The facile synthesis of the NPAuCu electrode demonstrated in the present study can be employed as a promising strategy in the development of high-performance electrocatalysts for energy and environmental applications.