铜改性黄铁矿催化剂的CO_(2)电催化还原性能研究

Copper modification of pyrite for CO_(2) electrochemical reduction

CO_(2)电催化还原合成高附加值燃料为CO_(2)转化利用提供了一条可持续发展的途径。然而,开发具有优异催化活性和产物选择性的电催化剂仍面临巨大的挑战。本研究制备了铜改性黄铁矿催化剂Cu_(x)Fe_(1−x)S_(2),采用XRD、XPS、SEM等表征分析方法研究了催化剂的物理化学性质,并研究了催化剂的CO_(2)电催化还原活性和产物选择性。实验结果表明,Cu掺杂可以调控催化剂纳米片的尺寸,同时可以抑制FeS_(2)在空气中的氧化。Cu_(0.33)Fe_(0.67)S_(2)比FeS_(2)表现出更好的催化反应活性,在(−1.5)−(−1.6)V vs.RHE,CO_(2)电催化还原的含碳产物法拉第效率为50.8%,电流密度为23.8 mA/cm^(2)。相比于FeS_(2)催化剂,电流密度提高了71.2%。Cu_(0.09)Fe_(0.91)S_(2)在−1.3 V vs.RHE下生成C_(3)H_(6)的法拉第效率为21.8%,显著高于目前文献中已报道的法拉第效率。因此,Cu_(x)Fe_(1−x)S_(2)是一种比较有前景的CO_(2)电催化还原催化剂。

CO_(2) electrocatalytic reduction to synthesize highly value-added fuels provides a sustainable path for CO_(2) conversion and utilization.Nevertheless,the development of electrocatalysts with high catalytic activity and product selectivity remains a major challenge.In this work,copper-doped FeS_(2) catalysts(Cu_(x)Fe_(1−x)S_(2))were prepared for CO_(2) electrochemical reduction.The physicochemical properties of the catalysts were studied by XRD,XPS,SEM and other characterization analysis methods.Experimental results show that Cu doping can control the size of the catalyst nanosheets and inhibit the oxidation of FeS_(2) in the air.Cu_(0.33)Fe_(0.67)S_(2) shows better catalytic activity for CO_(2) electrocatalytic reduction than FeS_(2).In the potential range of(−1.5)−(−1.6)V vs.RHE,the total efficiency of carbon-containing products of CO_(2) electrocatalytic reduction is 50.8%and its current density is 23.8 mA/cm^(2),which increases by 71.2%compared with FeS_(2) catalyst.The Faradaic efficiency of Cu_(0.09)Fe_(0.91)S_(2) to produce C_(3)H_(6) at−1.3 V vs.RHE is 21.8%,which is significantly higher than the value reported in the current literature.Thus,Cu_(x)Fe_(1−x)S_(2) is regarded as an excellent electrocatalyst for CO_(2) reduction.