Peripheral-nitrogen effects on the Ru1 centre for highly efficient propane dehydrogenation
Peripheral-nitrogen effects on the Ru1 centre for highly efficient propane dehydrogenation
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外围氮对 Ru1 中心的影响实现高效丙烷脱氢
DOI：
10.1038/s41929-023-00915-6
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发表时间：
2022-12
期刊：
影响因子：
37.8
通讯作者：
Tao Zhang
中科院分区：
文献类型：
--
作者：
Yanliang Zhou;Fenfei Wei;Haifeng Qi;Yicong Chai;Liru Cao;Jian Lin;Qiang Wan;Xiaoyan Liu;Yanan Xing;Sen Lin;Aiqin Wang;Xiaodong Wang;Tao Zhang
具有均匀金属活性中心的单原子催化剂显示出选择性控制的潜力。然而，它们在高温丙烷脱氢中的应用仍然具有挑战性。在这里，我们开发了一种高稳定性和高效的丙烷脱氢单原子催化剂，是基于氮掺杂碳（Ru 1 /NC）的Ru单原子。Ru 1 /NC的转换频率比纳米颗粒对应物的转换频率高至少三倍，导致丙烯选择性为约92%，在560 °C下具有较低的失活速率。实验和密度泛函理论研究揭示了Ru 1中心周围的外围N物种的重要作用。内壳层N使原子分散的Ru稳定以抑制结构敏感的丙烷裂化，而外壳层N促进Ru 1中心处的电子积累，诱导Ru 1和丙烯之间的显著电荷排斥以促进其解吸。单原子Ru位上的内壳层和外壳层N物种的联合作用有助于Ru 1 /NC的高效率。虽然低金属利用率的前景使单原子催化剂（SAC）成为人们关注的焦点，但反应性的固有限制仍然限制了它们在一小部分反应中的应用。在这里，作者扩展了SAC转换的剧目与氮掺杂，碳支撑，Ru单原子催化剂，利用外围N物种的影响，以促进丙烷脱氢。
Single-atom catalysts with uniform metal active sites show potential for selectivity control. However, their application to high-temperature propane dehydrogenation remains challenging. Here we develop a highly stable and efficient single-atom catalyst for propane dehydrogenation that is based on Ru single atoms on nitrogen-doped carbon (Ru 1 /NC). The turnover frequency of Ru 1 /NC is at least three times higher than that of nanoparticle counterparts, resulting in propylene selectivity of around 92% with a lower deactivation rate at 560 °C. Experimental and density functional theory studies reveal the important role of peripheral N species around the Ru 1 centre. The inner-shell N stabilizes the atomically dispersed Ru to inhibit structure-sensitive propane cracking, while the outer-shell N promotes electron accumulation at the Ru 1 centre, inducing a significant charge repulsion between Ru 1 and propylene to facilitate its desorption. The combined functions of inner-shell and outer-shell N species at single-atom Ru sites contribute to the high efficiency of Ru 1 /NC. While the promise of low metal utilization has brought single-atom catalysts (SACs) into the spotlight, intrinsic limits in reactivity still restrict their application to a small set of reactions. Here, the authors expand the repertoire of SAC transformations with a nitrogen-doped, carbon-supported, Ru single-atom catalyst that exploits the effect of peripheral N species to promote propane dehydrogenation.