Karapinar Dilan, Huan Ngoc Tran, Ranjbar Sahraie Nastaran, Li Jingkun, Wakerley David, Touati Nadia, Zanna Sandrine, Taverna Dario, Galvão Tizei Luiz Henrique, Zitolo Andrea, Jaouen Frédéric, Mougel Victor, Fontecave Marc
Laboratoire de Chimie des Processus Biologiques, CNRS UMR 8229, Collège de France, Sorbonne Université, PSL Research University, 11 Place Marcelin Berthelot, 75231, Paris Cedex 05, France.
Institut Charles Gerhardt Montpellier (UMR 5253), CNRS, Université de Montpellier ENSCM, 2 place Eugène Bataillon, 34095, Montpellier, France.
Angew Chem Int Ed Engl. 2019 Oct 14;58(42):15098-15103. doi: 10.1002/anie.201907994. Epub 2019 Sep 11.
It is generally believed that CO electroreduction to multi-carbon products such as ethanol or ethylene may be catalyzed with significant yield only on metallic copper surfaces, implying large ensembles of copper atoms. Here, we report on an inexpensive Cu-N-C material prepared via a simple pyrolytic route that exclusively feature single copper atoms with a CuN coordination environment, atomically dispersed in a nitrogen-doped conductive carbon matrix. This material achieves aqueous CO electroreduction to ethanol at a Faradaic yield of 55 % under optimized conditions (electrolyte: 0.1 m CsHCO , potential: -1.2 V vs. RHE and gas-phase recycling set up), as well as CO electroreduction to C -products (ethanol and ethylene) with a Faradaic yield of 80 %. During electrolysis the isolated sites transiently convert into metallic copper nanoparticles, as shown by operando XAS analysis, which are likely to be the catalytically active species. Remarkably, this process is reversible and the initial material is recovered intact after electrolysis.
一般认为，只有在金属铜表面上，CO电还原为多碳产物（如乙醇或乙烯）才可能以可观的产率被催化，这意味着需要大量的铜原子团簇。在此，我们报道了一种通过简单热解路线制备的廉价Cu-N-C材料，其独特之处在于单个铜原子以CuN配位环境原子分散在氮掺杂的导电碳基质中。在优化条件下（电解质：0.1 m CsHCO，电位：相对于可逆氢电极-1.2 V以及气相循环装置），该材料实现了将CO在水溶液中电还原为乙醇，法拉第产率为55%，以及将CO电还原为C产物（乙醇和乙烯），法拉第产率为80%。在电解过程中，如原位X射线吸收光谱分析所示，孤立位点会瞬时转化为金属铜纳米颗粒，这些纳米颗粒可能是催化活性物种。值得注意的是，这个过程是可逆的，电解后初始材料完好无损地被回收。
