CuGa_(2)电催化CO_(2)还原制合成气

CO_(2) reduction to syngas by CuGa_(2) electrocatalysis

碳达峰、碳中和是实现我国绿色可持续发展发展的重大战略需求。合成气作为现代化工生产的重要基础原料,其传统的制备方法高度依赖化石能源,导致了大量的温室气体排放利用可再生电力驱动的电催化CO_(2)还原制合成气技术作为一种环保且可持续的替代方案,近年来受到广泛的研究与关注。虽然已有研究探讨了不同催化剂对电催化CO_(2)还原制合成气的V(H_(2))/V(CO)的影响,但对于在单一催化剂上实现对合成气产物中H_(2)和CO选择性的有效调控仍具有挑战性。为了实现在单一催化剂上对合成气产物中V(H_(2))/V(CO)的选择性调控,本研究采用高温固相合成工艺合成了CuGa_(2)金属间化合物,用以作为电催化剂来实现高选择性、可调性电催化CO_(2)还原制合成气,并通过SEM、EDS、XRD和XPS等一系列表征分析手段,研究了CuGa_(2)金属间化合物的理化特性与电化学性能,并探究了CuGa_(2)金属间化合物在电催化CO_(2)还原过程中的相关催化机理。研究结果表明,该催化剂作为CuGa_(2)和少量金属氧化物的混合物,能够通过改变电解液浓度、调控pH值的手段,显著调控其对于电催化CO_(2)还原反应(eCO_(2)RR)和析氢反应(HER)的选择性,从而调控合成气产物中的V(H_(2))/V(CO)。此外,不同电位对V(H_(2))/V(CO)的影响测试结果显示,通过控制施加电位,可以调节CuGa_(2)催化剂活性位点的利用率,进而改变eCO_(2)RR和HER的选择性,实现合成气产物中V(H_(2))/V(CO)在0.3~4内可调。

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 fosil fuels for its preparation,resulting in significant greenhouse gas emissions.In recent years,the technology of electrocatalytic CO_(2) reduction to syngas driven by renewable electricity has emerged as an environmentally friendly and sustainable alternative,garnering extensive research interest.While previous studies have explored the impact of different catalysts on the V(H_(2))/V(CO)ratio in syngas produced via electrocatalytic CO_(2) reduction,effectively tuning the selectivity of H_(2) and CO using a single catalyst remains a challenge.To achieve selective modulation of the V(H_(2))/V(CO)ratio in syngas products with a single catalyst,this study synthesized CuGa intermetallic compounds through a high-temperature solid-state synthesis process.These compounds were employed as electrocatalysts to enable high selectivity and tunability in the electrocatalytic CO_(2) reduction to syngas.A range of characterization techniques,including SEM,EDS,XRD,and XPS,were used to investigate the physicochemical properties and electrochemical performance of the CuGa_(2) intermetallics,as well as their catalytic mechanisms during the electrocatalytic CO_(2) reduction process.The results indicated that this catalyst,consisting of a mixture of CuGa_(2) and a small amount of metal oxides,could significantly adjust its selectivity for the electrocatalytic CO_(2) reduction reaction(eCO,RR)and the hydrogen evolution reaction(HER)by varying electrolyte concentration and pH,thereby modulating the V(H_(2))/V(CO)ratio in the syngas produced.Moreover,tests examining the impact of different applied potentials on the V(H_(2))/V(CO)ratio demonstrated that controlling the applied potential allows for the adjustment of active site utilization in the CuGa_(2) catalyst,thus altering the selectivity of both eCO_(2)RR and HER.This enables the V(H_(2))/V(CO)ratio in syngas products to be tuned within a range of 0.3 to 4.