Keke Wang , Zhang Ruichao , Zhou Bolin , Qiang Li , Zhou Mengmeng , Hai Min Shen , Wang Qin , Jiexiang Xia , Huaming Li , Qun Yi
2025 JOURNAL OF COLLOID AND INTERFACE SCIENCE 677:872-881
Abstract：
The highly selective conversion of CO2 into valuable C2H4 is a highly important but particularly challenging reaction. Herein, the metal–organic frameworks MOF-74(Cu) with infinite Cu(II)-O chains and Cu-BTC (BTC=benzene-1,3,5-tricarboxylate) with paddle-wheel binuclear Cu(II) clusters are used as precursors. These MOFs are reduced by NaBH4 to obtain Cu0/Cuδ+-based photocatalysts denoted as R-MOF-74(Cu) and R-Cu-BTC, respectively. Significantly, R-MOF-74(Cu) achieves a high selectivity of 90.2 % for C2H4 with a yield rate of 6.5 μmol g−1 within 5 h due to its high Cu+ content. To the best of our knowledge, this C2H4 product selectivity is a record high among all the photocatalysts reported so far for photocatalytic CO2 reduction. In contrast, R-Cu-BTC only forms CO as a product with a cumulative yield of 0.7 μmol g−1 within 5 h. Photoelectrochemical characterization and electron paramagnetic resonance results show that R-MOF-74(Cu) has low interfacial transfer resistance, high photogenerated electron separation efficiency, and excellent CO2 activation and water oxidation performance. In addition, in situ Fourier transform infrared spectroscopy is used to determine the possible reaction pathway from CO2 to C2H4 over R-MOF-74(Cu). This work demonstrates the great potential of MOF-derived photocatalysts for the conversion of CO2 into C2H4 and provides guidance for future photocatalyst development.
将二氧化碳高选择性地转化为有价值的乙烯（C2H4）是一项非常重要但尤为具有挑战性的反应。在此研究中，使用了含有无限Cu(II)-O链的金属有机框架MOF-74(Cu)和含轮桨式双核Cu(II)簇的Cu-BTC（BTC=苯-1,3,5-三羧酸盐）作为前驱体。这些金属有机框架通过NaBH4还原得到基于Cu0/Cuδ+的光催化剂，分别标记为R-MOF-74(Cu)和R-Cu-BTC。值得注意的是，由于其高的Cu+含量，R-MOF-74(Cu)实现了90.2%的高乙烯选择性，在5小时内产率为6.5 μmol g^-1。据我们所知，这种乙烯产物选择性在所有已报道的用于光催化还原二氧化碳的光催化剂中是最高的。相反，R-Cu-BTC仅产生一氧化碳，5小时内的累计产率为0.7 μmol g^-1。光电化学表征和电子顺磁共振结果表明，R-MOF-74(Cu)具有低的界面转移电阻、高的光生电子分离效率以及优异的二氧化碳活化和水氧化性能。此外，原位傅里叶变换红外光谱被用来确定从二氧化碳到乙烯在R-MOF-74(Cu)上的可能反应路径。这项工作展示了MOF衍生的光催化剂在二氧化碳转化为乙烯方面的巨大潜力，并为未来的光催化剂开发提供了指导。
