Cai Xiao, Hu Weigang, Xu Shun, Yang Dan, Chen Mingyang, Shu Miao, Si Rui, Ding Weiping, Zhu Yan
School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China.
Center for Green Innovation, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China.
J Am Chem Soc. 2020 Mar 4;142(9):4141-4153. doi: 10.1021/jacs.9b07761. Epub 2020 Feb 24.
Unveiling the mystery of the contribution of nonsurface or noninterface sites in a catalyst to its catalytic performance remains a great challenge because of the difficulty in capturing precisely structural information (surface plus inner) encoded in the catalyst. This work attempts to elucidate the critical role of the internal vacancy in an atomically precise 24-atom gold cluster in regulating the catalytic performance on the hydrogenation reaction of CO. The experiment results show that the Au cluster with internal vacancy can mitigate sintering and exhibit high catalytic activity under relatively harsh reaction conditions, in contrast to the structurally similar Au cluster without internal vacancy. Our computational study suggests that the internal vacancy in Au provides the cluster with much more structural flexibility, which may be crucial to resisting the aggregation of the cluster and further postponing the deactivation. The hydrogenation and coupling stages of the reaction intermediates are proposed to explain the potential reaction pathway of CO with H on the Au catalyst with internal vacancy.
揭示催化剂中非表面或非界面位点对其催化性能的贡献之谜仍然是一项巨大的挑战，因为难以精确获取催化剂中编码的结构信息（表面加内部）。这项工作试图阐明原子精确的24原子金簇中的内部空位在调节CO加氢反应催化性能方面的关键作用。实验结果表明，与结构相似但无内部空位的金簇相比，具有内部空位的金簇可以减轻烧结，并在相对苛刻的反应条件下表现出高催化活性。我们的计算研究表明，金中的内部空位为簇提供了更大的结构灵活性，这可能对抵抗簇的聚集并进一步延缓失活至关重要。提出了反应中间体的加氢和偶联阶段，以解释CO与具有内部空位的金催化剂上的H的潜在反应途径。
