Achieving carbon peak and carbon neutrality is a critical strategic requirement for China's green and sustainable development.Syngas,as a vital raw material for modern chemical production,traditionally relies heavily on fossil fuels for its preparation,resulting insignificant greenhouse gas emissions. In recent years, the technology of electrocatalytic CO2 reduction to syngas driven by renewableelectricity has emerged as an environmentally friendly and sustainable alternative,garnering extensive research interest.While previousstudies have explored the impact of different catalysts on the V(H2)/V(CO) ratio in syngas produced via electrocatalytic CO2 reduction,effectively tuning the selectivity of H2 and CO using a single catalyst remains a challenge. To achieve selective modulation of the V(H2) /V(CO) ratio in syngas products with a single catalyst,this study synthesized CuGa2 intermetallic compounds through a high-temperaturesolid-state synthesis process. These compounds were employed as electrocatalysts to enable high selectivity and tunability in theelectrocatalytic CO2 reduction to syngas.A range of characterization techniques, including SEM, EDS, XRD, and XPS, were used toinvestigate the physicochemical properties and electrochemical performance of the CuGa2 intermetallics, as well as their catalytic mechanisms during the electrocatalytic CO2 reduction process. The results indicated that this catalyst,consisting of a mixture of CuGa2and a small amount of metal oxides,could significantly adjust its selectivity for the electrocatalytic CO2 reduction reaction (eCO2RR) and the hydrogen evolution reaction (HER) by varying electrolyte concentration and pH,thereby modulating the V(H2)/V(CO) ratio in the syngas produced.Moreover,tests examining the impact of different applied potentials on the V(H2)/V(CO) ratio demonstrated that controlling the applied potential allows for the adjustment of active site utilization in the CuGa2 catalyst,thus altering the selectivity of both eCO2RR and HER. This enables the V(H2)/V(CO) ratio in syngas products to be tuned within a range of 0.3 to 4.

张军峰(1980—),男,河北廊坊人,高级工程师。E-mail:16260033@ceic.com

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ZHANG Junfeng,WEI Shuzhou,WANG Chang,et al. CO2 reduction to syngas by CuGa2 electrocatalysis[J].Clean Coal Technology,2024,30(11):97−103.