Achieving the high selectivity of multicarbon (C2+) products during the acidic CO2 electroreduction remains a formidable challenge due to the serious hydrogen evolution reaction. Herein we report a Cu-based tandem catalyst by implanting molecular cobalt(II) tetraphenylporphyrin (CoTPP) into a porous Cu2O (Cu2O-CoTPP) for improving the C2+ selectivity in acidic media. Specially, CoTPP, as a CO-selective catalyst, is predominantly trapped in the nanopores of Cu2O with the assistance of negative-pressure ultrasonic. The CO2-CO and CO-C2+ tandem catalysis on Cu2O-CoTPP, cooperating with the pore confinement effect of porous Cu2O, boosts the local CO concentration and *CO coverage on Cu sites, evidenced by in-situ Raman spectra and finite element simulations. As a result, Cu2O-CoTPP attains a C2+ Faradaic efficiency of 91.2 % at an industrial-level current density of 800 mA/cm2 in an acidic environment (pH = 1.9), higher than the one (70.6 %) on pristine Cu2O. Meanwhile, such a tandem catalyst obtains a high single-pass carbon efficiency of 52.6 % and the good catalytic stability of at least 20 h. This study offers a spatially-confined Cu-based tandem catalyst for selective C2+ production, presenting the promising application in acidic environments.

中文翻译：

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四苯基卟啉钴 (II) 被捕获在 Cu2O 的孔中，以增强 C2+ 对酸性 CO2 电还原的选择性


由于严重的析氢反应，在酸性 CO2 电还原过程中实现多碳 (C2+) 产物的高选择性仍然是一个艰巨的挑战。在此，我们报道了一种铜基串联催化剂，通过将分子钴（II）四苯基卟啉（CoTPP）植入多孔Cu2O（Cu2O-CoTPP）中来提高酸性介质中的C2+选择性。特别地，CoTPP作为CO选择性催化剂，在负压超声波的辅助下主要被捕获在Cu2O的纳米孔中。原位拉曼光谱和有限元模拟证明，Cu2O-CoTPP 上的 CO2-CO 和 CO-C2+ 串联催化，与多孔 Cu2O 的孔限域效应相配合，提高了 Cu 位点上的局部 CO 浓度和*CO 覆盖率。结果，在酸性环境（pH = 1.9）下，Cu2O-CoTPP 在工业级电流密度 800 mA/cm2 下实现了 91.2% 的 C2+ 法拉第效率（70.6%），高于原始 Cu2O 的 C2+ 法拉第效率（70.6%）。同时，这种串联催化剂获得了52.6%的高单程碳效率和至少20 h的良好催化稳定性。这项研究提供了一种用于选择性 C2+ 生产的空间受限铜基串联催化剂，在酸性环境中具有广阔的应用前景。