Controllable Pd@Cu₂O Schottky junction interface with improved anti-poisoning effect for efficiently electroreduction of CO₂ into syngas

Syngas is an important precursor to numerous value-added products and can be produced by the electrochemical CO2 reduction reaction (ECO2 RR). However, developing high-performance CO2-to-syngas based-Cu2O electrocatalysts remains challenging. Herein, a series of ultrathin two-dimensional (2D) Pd@Cu2O Schottky junction catalysts was designed to afford finely tunable syngas productivity across a wide potential range (-0.37 V to -0.87 V vs RHE) with a Faraday efficiency >80 % through the ECO2 RR. Detailed experiments and Density functional theory (DFT) calculations revealed that the 2D structure provided a high interfacial contact area to promote charge transfer, leading to an improved charge distribution at the Schottky junction interface to accelerate CO2 activation and stable Cu2O. CO2 center dot- readily participated in the subsequent two proton transfer step with neighboring PdH to form CO, and the competitive hydrogen evolution reaction was significantly inhibited. This work provides a new avenue to efficiently convert electrocatalytic CO2 to syngas by regulating the interface configuration.