福州大学林森研究团队报道了调节单原子催化剂中外围氮掺杂促进丙烷脱氢。相关研究成果发表在2024年10月24日出版的《德国应用化学》。

对于单原子催化剂（SACs），金属位点附近的掺杂剂对催化性能有显著影响。然而，远离金属中心的掺杂剂的作用及其工作机制仍有待阐明。

该文中，研究人员进行了密度泛函理论驱动的研究，以调节石墨烯基SACs中的外围氮掺杂剂，特别关注Ir1 SAC，用于丙烷脱氢（PDH）。研究发现，与仅具有第一和第二壳N物种的致密掺杂模型相比，增加N掺杂剂和Ir1位点之间的距离会导致反应过程的能量变化不同。

所提出的随机掺杂模型从统计学上证明，在更远的壳中增加N掺杂剂不仅可以提高Ir1的活性，还可以保持对丙烯的高选择性，并进行了实验测试的验证。随机N掺杂剂对Ir1 d带中心的调制有效地改变了反应中间体的结合强度，从而优化了PDH的势能面。

研究结果加深了对金属位点周围掺杂态的理解，并为非均相催化中的掺杂工程提供了重要启示。

附：英文原文

Title: Regulating Peripheral Nitrogen Dopants in Single-Atom Catalysts to Enhance Propane Dehydrogenation

Author: Fenfei Wei, Liru Cao, Bingqing Ge, Yang Chen, Xiaoli Pan, Yicong Chai, Rizheng Jing, Xixi Hu, Xiaodong Wang, Jian Lin, Sen Lin

Issue&Volume: 2024-10-24

Abstract: For single-atom catalysts (SACs), the dopants situated near the metal site have demonstrated a significant impact on the catalytic properties. However, the effect of dopants situated further away from the metal centers and their working mechanisms remain to be elucidated. Herein, we conduct density functional theory-driven studies on regulating the peripheral nitrogen dopants in graphene-based SACs, with a particular focus on Ir1 SAC, for propane dehydrogenation (PDH). It is found that increasing the distance between the N dopant and the Ir1 site results in a different energy change for the reaction process compared to the dense doping model with only first and second-shell N species. The proposed stochastic doping models demonstrate statistically that increasing the N dopant in farther shells not only enhances the activity of Ir1 but also maintains a high selectivity for propene, which is verified by experimental tests. The modulation of the d-band center of Ir1 by stochastic N dopants effectively modifies the binding strength of reaction intermediates, thereby enabling the optimization of the potential energy surface of PDH. These results deepen the understanding of dopant states around metal sites and provide an important implication for the doping engineering in heterogeneous catalysis.

DOI: 10.1002/anie.202416912

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202416912