We achieved highly selective electrochemical reduction of CO₂ to C₂H₄ (faradaic efficiency of 25%) by crystalline copper phthalocyanine (CuPc) supported on carbon black. Remarkably, noncrystalline CuPc generated by treatment of crystalline CuPc with sulfuric acid did not give C₂H₄ selectively, suggesting that catalyst crystallinity is crucial for the selective conversion of CO₂ to C₂H₄. The stability of crystalline CuPc under electrochemical reduction conditions was also evaluated, showing that crystalline CuPc can selectively convert CO to C₂H₄ in the initial stage (<10 000 s), as long as the crystallinity of the catalyst is maintained.

中文翻译：

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结晶铜（II）酞菁催化剂，用于在水性介质中电化学还原二氧化碳

我们通过负载在炭黑上的结晶铜酞菁（CuPc）实现了高选择性的电化学还原，将CO ₂还原为C ₂ H ₄（法拉第效率为25％）。值得注意的是，通过用硫酸处理结晶的CuPc而生成的非晶态的CuPc没有选择性地产生C ₂ H ₄，这表明催化剂的结晶度对于将CO ₂选择性转化为C ₂ H ₄至关重要。还评估了结晶CuPc在电化学还原条件下的稳定性，表明结晶CuPc可以选择性地将CO转化为C ₂ H _4。 在初始阶段（<10000 s），只要保持催化剂的结晶度即可。