用于将CO2转化为增值化学品或燃料的稳定和选择性电催化剂的开发在其减轻人为碳排放的潜力方面获得了极大的兴趣。大多数电催化剂都是在纯CO2下测试的;然而,工业出口烟气含有大量杂质,如NO和SO2,它们使电催化剂中毒并改变产物选择性。开发耐此类杂质的电催化剂对于商业实施是必不可少的。在这里,我们制备了双层多孔电催化剂,即,Sn,Bi,在,在多孔铜泡沫网上(Sn/Cu-f,Bi/Cu-f,和In/Cu-f)通过两步电沉积工艺,并使用这些电极将CO2电化学还原为甲酸盐。观察到,与涂覆在Cu网上的催化剂相比,双层多孔电催化剂表现出高的CO2还原活性。在双层多孔电催化剂中,Sn/Cu-f和Bi/Cu-f电催化剂对甲酸盐生产的法拉第效率(FE)超过80%,甲酸根部分电流密度分别约为-16和-10.4mAcm-2,在-1.02V对RHE。In/Cu-f电催化剂显示近40%的甲酸酯FE,在-1.22V与RHE的甲酸酯部分电流密度为-15mAcm-2。我们研究了NO和SO2杂质的影响(500ppm的NO,800ppm的SO2和500ppm的NO800ppm的SO2)在这些电催化剂上对甲酸盐的选择性和稳定性。观察到Bi/Cu-f电催化剂显示出50小时的稳定性,甲酸酯为80±5%,在NO和SO2与CO2混合的情况下,Sn/Cu-f显示出18h的稳定性,效率高于80±5%。此外,我们研究了在15-100%CO2范围内使用Sn/Cu-f和Bi/Cu-f催化剂对CO2浓度的影响,其中观察到甲酸FEs为45-80%。
The development of stable and selective electrocatalysts for converting CO2 to value-added chemicals or fuels has gained much interest in terms of their potential to mitigate anthropogenic carbon emissions. Most of the electrocatalysts are tested under pure CO2; however, industrial outlet flue gas contains numerous impurities, such as NO and SO2, which poison the electrocatalysts and alter the product selectivity. Developing electrocatalysts that are resistant to such impurities is essential for commercial implementation. Herein, we prepared bilayer porous electrocatalysts, namely, Sn, Bi, and In, on porous Cu foam mesh (Sn/Cu-f, Bi/Cu-f, and In/Cu-f) by a two-step electrodeposition process and employed these electrodes for the electrochemical reduction of CO2 to formate. It was observed that the bilayer porous electrocatalysts exhibited high CO2 reduction activity compared to catalysts coated on a Cu mesh. Among bilayer porous electrocatalysts, Sn/Cu-f and Bi/Cu-f electrocatalysts showed more than 80% faradaic efficiency (FE) toward formate production, with a formate partial current density of around -16 and -10.4 mA cm-2, respectively, at -1.02 V vs RHE. In/Cu-f electrocatalyst showed nearly 40% formate FE with formate partial current density of -15 mA cm-2 at -1.22 V vs RHE. We investigated the effect of NO and SO2 impurities (500 ppm of NO, 800 ppm of SO2, and 500 ppm of NO + 800 ppm of SO2) on these electrocatalysts\' selectivity and stability toward formate. It was observed that the Bi/Cu-f electrocatalyst showed 50 h stability with 80 ± 5% formate FE, and Sn/Cu-f showed 18 h stability with above 80 ± 5% efficiency in the presence of NO and SO2 mixed with CO2. Furthermore, we studied the effect of CO2 concentration with Sn/Cu-f and Bi/Cu-f catalysts in the range of 15-100% CO2, for which formate FEs of 45-80% were observed.