纯计算ACS Catal.: 三原子金属团簇催化NRR

2022年11月25日，ACS Catal.在线发表了中科院化学所骆智训研究员课题组的研究论文，题目为《On the Nature of Three-Atom Metal Cluster Catalysis for N2 Reduction to Ammonia》。

催化氮气(N2)活化和还原合成氨一直是人们研究的热点。团簇修饰催化剂因其独特的活性位点和最大的协同效应被认为是很有前景的N2活化催化剂。然而，金属团簇本身的性质还没有被完全揭示出来。在此研究中，作者报道了第三和第四周期元素中所有20种过渡金属的三原子金属团簇(three-atom metal cluster, M3)的N2活化和还原。通过考虑三个关键过程来评估这些M3团簇的催化作用，包括N2分解、氢化和NH3脱附。与TMII和TMIII团簇(即6B-8B和1B-2B)相比，M3团簇(3B-5B)的TMI系列能够自发地支持N2分解。根据这三个标准，确定Y3、Sc3、Zr3和Nb3为氨合成的合格候选者。这些团簇具有较好的空穴位点N2吸附和较强的轨道杂化，金属的d轨道电子对N2的π*和π/σ轨道有着反馈作用(backdonation)。采用石墨烯支撑的Y3和Nb3团簇(Y3/G和Nb3/G)对氨合成进行了进一步研究，表明这种M3团簇具有优异的活性和潜在的应用价值。该工作验证了三原子团簇催化的有效性，并指导了高效催化剂的设计。

图1 N2吸附结构和差分电荷密度

图2 N2分解的吉布斯自由能变化

图3 2N*加氢过程

图4 NRR的反应路径

图5 PDOS、COHP和分子轨道能级

图6 N2分解过渡态、加氢反应势垒和NH3脱附能

图7 三原子金属团簇结构、N2吸附差分电荷密度和AIMD

图8 NRR的反应路径

【论文链接】

Cui, C., Zhang, H., Cheng, R. et al. On the Nature of Three-Atom Metal Cluster Catalysis for N2 Reduction to Ammonia. ACS Catal.,2022, 12, 14964-14975. https://doi.org/10.1021/acscatal.2c04146

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