Facile Synthesis of Nanostructural High-Performance Cu-Pb Electrocatalysts for CO2 Reduction

Nanostructure and crystallinity of transition metals play an important role in catalyzing carbon dioxide electroreduction (CO2ER) where Cu is a typical electrocatalyst with a wide variety of products and Pb has a high overpotential for H-2 evolution and is selective toward formic acid. In this study, 3D hierarchical nanostructures of Cu-Pb catalyst are prepared by a two-step electrodepositing-annealing-electroreduction approach (EAE). Cu nanowires (Cu NWs) of 200-400 nm diameter are built on the surface of commercial nickel foam substrates through an EAE step. Then, Pb nanoparticles with diameter of 5-10 nm are uniformly created on the surface of Cu NWs by a second EAE step. The nanostructural Cu-Pb electrodes catalyze CO2ER at a current density of -9.35 mA cm(-2) (at -0.93 V vs reversible hydrogen electrode (RHE)). The H-2 evolution is suppressed by 35.6% and CO and HCOOH are enhanced by 29.6% and 9.2%, respectively, as compared with Cu NWs. The protocol proposed in this study provides a simple and straightforward approach for preparing high-performance, hierarchical nanostructures of Cu-Pb bimetal catalyst for CO2ER.