One of the biggest obstacles to the light-driven conversion of greenhouse gas CO₂ into high value-added multi-carbon compounds is manipulating the C–C coupling reaction. Herein, we propose using a symbiotic effect to construct asymmetric dual active sites, namely doping CuInS₂ (CIS) with single atomic Ag, accompanied by the formation of sulfur vacancies (S_v). Thus, S_v and the neighbouring In metal atom double sites are constructed, and CO₂ photoreduction products undergo a transformation from C₁ products to C₂H₄. Meanwhile, the doped Ag plays a role in capturing and transferring photogenerated electrons, improving the reduction rate. The generation rate of C₂H₄ is 53.8 μmol g⁻¹ h⁻¹ with a selectivity of 98.8%. Based on the number of transferred electrons, the catalytic activity of 2%Ag/CuInS₂ (2%Ag/CIS) is 90 times that of CIS. Experimental and theoretical calculations verify that the key intermediates *CO and *CHO adsorbed on S_v and In sites, respectively, are propitious to promote the occurrence of the C–C coupling reaction owing to the reasonable distance, asymmetric electron distribution and distinct adsorption capacity. Accordingly, the findings provide a new strategy for designing asymmetric catalytic active sites for the selective photosynthesis of multi-carbon products from CO₂.

中文翻译：

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通过共生效应构建不对称双活性位点实现CO2高效选择性光还原为C2H4


将温室气体 CO ₂ 光驱动转化为高附加值多碳化合物的最大障碍之一是操纵 C-C 偶联反应。在此，我们提出利用共生效应构建不对称双活性位点，即用单原子Ag掺杂CuInS ₂ (CIS)，同时形成硫空位(S _v ) 。由此，构建了S _v 和邻近的In金属原子双位点，并且CO ₂ 光还原产物经历了从C ₁ 产物到C ₂ H ₄ 。同时，掺杂的Ag起到捕获和转移光生电子的作用，提高还原率。 C ₂ H ₄ 的生成率为 53.8 μmol g ⁻¹ h ⁻¹ ，选择性为 98.8%。根据转移电子数计算，2%Ag/CuInS ₂ (2%Ag/CIS) 的催化活性是 CIS 的 90 倍。实验和理论计算验证了关键中间体*CO和*CHO分别吸附在S _v 和In位点上，由于合理的距离、不对称性，有利于促进C-C偶联反应的发生。电子分布和独特的吸附能力。因此，这些发现为设计不对称催化活性位点以选择性光合作用CO ₂ 多碳产物提供了一种新策略。