Chen Xiaowen, Peng Mi, Cai Xiangbin, Chen Yunlei, Jia Zhimin, Deng Yuchen, Mei Bingbao, Jiang Zheng, Xiao Dequan, Wen Xiaodong, Wang Ning, Liu Hongyang, Ma Ding
Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang, P. R. China.
School of Materials Science and Engineering, University of Science and Technology of China, Shenyang, P. R. China.
Nat Commun. 2021 May 11;12(1):2664. doi: 10.1038/s41467-021-22948-w.
Metal nanoparticle (NP), cluster and isolated metal atom (or single atom, SA) exhibit different catalytic performance in heterogeneous catalysis originating from their distinct nanostructures. To maximize atom efficiency and boost activity for catalysis, the construction of structure-performance relationship provides an effective way at the atomic level. Here, we successfully fabricate fully exposed Pt clusters on the defective nanodiamond@graphene (ND@G) by the assistance of atomically dispersed Sn promoters, and correlated the n-butane direct dehydrogenation (DDH) activity with the average coordination number (CN) of Pt-Pt bond in Pt NP, Pt cluster and Pt SA for fundamentally understanding structure (especially the sub-nano structure) effects on n-butane DDH reaction at the atomic level. The as-prepared fully exposed Pt cluster catalyst shows higher conversion (35.4%) and remarkable alkene selectivity (99.0%) for n-butane direct DDH reaction at 450 °C, compared to typical Pt NP and Pt SA catalysts supported on ND@G. Density functional theory calculation (DFT) reveal that the fully exposed Pt clusters possess favorable dehydrogenation activation barrier of n-butane and reasonable desorption barrier of butene in the DDH reaction.
金属纳米颗粒（NP）、团簇和孤立的金属原子（或单原子，SA）在多相催化中表现出不同的催化性能，这源于它们独特的纳米结构。为了最大化原子效率并提高催化活性，构建结构-性能关系在原子水平上提供了一种有效方法。在此，我们借助原子分散的Sn促进剂，成功地在缺陷纳米金刚石@石墨烯（ND@G）上制备了完全暴露的Pt团簇，并将正丁烷直接脱氢（DDH）活性与Pt NP、Pt团簇和Pt SA中Pt-Pt键的平均配位数（CN）相关联，以便从根本上在原子水平理解结构（特别是亚纳米结构）对正丁烷DDH反应的影响。与负载在ND@G上的典型Pt NP和Pt SA催化剂相比，所制备的完全暴露的Pt团簇催化剂在450℃下对正丁烷直接DDH反应表现出更高的转化率（35.4%）和显著的烯烃选择性（99.0%）。密度泛函理论计算（DFT）表明，完全暴露的Pt团簇在DDH反应中具有有利的正丁烷脱氢活化能垒和合理的丁烯脱附能垒。
