Structural Relaxation Enabled by Internal Vacancy Available in a 24-Atom Gold Cluster Reinforces Catalytic Reactivity
Structural Relaxation Enabled by Internal Vacancy Available in a 24-Atom Gold Cluster Reinforces Catalytic Reactivity
复制标题
24 原子金簇中的内部空位实现结构松弛，增强催化反应性
DOI：
10.1021/jacs.9b07761
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发表时间：
2020-03-04
影响因子：
15
通讯作者：
Zhu, Yan
中科院分区：
文献类型：
--
作者：
Cai, Xiao;Hu, Weigang;Zhu, Yan
揭开神秘的非表面或非界面的网站在催化剂的催化性能的贡献仍然是一个巨大的挑战，因为很难捕捉到精确的结构信息（表面加内部）编码的催化剂。本工作试图阐明原子级精确的24原子金簇中的内部空位在调节CO2加氢反应的催化性能中的关键作用。实验结果表明，与结构相似的无空位Au-25簇合物相比，含空位的Au-24簇合物在相对苛刻的反应条件下，能有效地抑制烧结，表现出较高的催化活性。计算结果表明，Au-24的内部空位为团簇提供了更大的结构灵活性，这可能是抵抗团簇聚集和进一步推迟失活的关键。提出了反应中间体的加氢和偶联阶段来解释CO2与H2-在具有内部空位的Au-24催化剂上的潜在反应途径。
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 CO2. The experiment results show that the Au-24 cluster with internal vacancy can mitigate sintering and exhibit high catalytic activity under relatively harsh reaction conditions, in contrast to the structurally similar Au-25 cluster without internal vacancy. Our computational study suggests that the internal vacancy in Au-24 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 CO2 with H-2 on the Au-24 catalyst with internal vacancy.