Boosting Tunable Syngas Formation via Electrochemical CO2Reduction on Cu/In2O3Core/Shell Nanoparticles

In this work, monodisperse core/shell Cu/In2O3nanoparticles (NPs) were developed to boost efficient and tunable syngas formation via electrochemical CO2reduction for the first time. The efficiency and composition of syngas production on the developed carbon-supported Cu/In2O3catalysts are highly dependent on the In2O3shell thickness (0.4–1.5 nm). As a result, a wide H2/CO ratio (4/1 to 0.4/1) was achieved on the Cu/In2O3catalysts by controlling the shell thickness and the applied potential (from −0.4 to −0.9 V vs reversible hydrogen electrode), with Faraday efficiency of syngas formation larger than 90%. Specifically, the best-performing Cu/In2O3catalyst demonstrates remarkably large current densities under low overpotentials (4.6 and 12.7 mA/cm2at −0.6 and −0.9 V, respectively), which are competitive with most of the reported systems for syngas formation. Mechanistic discussion implicates that the synergistic effect between lattice compression and Cu doping in the In2O3shell may enhance the binding of *COOH on the Cu/In2O3NP surface, leading to the enhanced CO generation relative to Cu and In2O3catalysts. This report demonstrates a new strategy to realize efficient and tunable syngas formation via rationally designed core/shell catalyst configuration.