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.
将二氧化碳高選擇性地轉化為有價值的乙烯（C2H4）是一項非常重要但尤為具有挑戰性的反應。在此研究中，使用了含有無限Cu(II)-O鍊的金屬有機框架MOF-74(Cu)和含輪槳式雙核Cu(II)簇的Cu-BTC（BTC=苯-1,3,5-三羧酸鹽）作為前驅體。這些金屬有機框架通過NaBH4還原得到基于Cu0/Cuδ+的光催化劑，分别标記為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)實現了90.2%的高乙烯選擇性，在5小時内産率為6.5 μmol g^-1。據我們所知，這種乙烯産物選擇性在所有已報道的用于光催化還原二氧化碳的光催化劑中是最高的。相反，R-Cu-BTC僅産生一氧化碳，5小時内的累計産率為0.7 μmol g^-1。光電化學表征和電子順磁共振結果表明，R-MOF-74(Cu)具有低的界面轉移電阻、高的光生電子分離效率以及優異的二氧化碳活化和水氧化性能。此外，原位傅裡葉變換紅外光譜被用來确定從二氧化碳到乙烯在R-MOF-74(Cu)上的可能反應路徑。這項工作展示了MOF衍生的光催化劑在二氧化碳轉化為乙烯方面的巨大潛力，并為未來的光催化劑開發提供了指導。
