Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 110016, P. R. China.
School of Materials Science and Engineering, University of Science and Technology of China, Shenyang, 110016, P. R. China.
Nat Commun. 2023 May 5;14(1):2588. doi: 10.1038/s41467-023-38361-4.
Single-site pincer-ligated iridium complexes exhibit the ability for C-H activation in homogeneous catalysis. However, instability and difficulty in catalyst recycling are inherent disadvantages of the homogeneous catalyst, limiting its development. Here, we report an atomically dispersed Ir catalyst as the bridge between homogeneous and heterogeneous catalysis, which displays an outstanding catalytic performance for n-butane dehydrogenation, with a remarkable n-butane reaction rate (8.8 mol·g·h) and high butene selectivity (95.6%) at low temperature (450 °C). Significantly, we correlate the BDH activity with the Ir species from nanoscale to sub-nanoscale, to reveal the nature of structure-dependence of catalyst. Moreover, we compare Ir single atoms with Pt single atoms and Pd single atoms for in-depth understanding the nature of metal-dependence at the atomic level. From experimental and theoretical calculations results, the isolated Ir site is suitable for both reactant adsorption/activation and product desorption. Its remarkable dehydrogenation capacity and moderate adsorption behavior are the key to the outstanding catalytic activity and selectivity.
单原子固载手性钳式铱配合物在均相催化中表现出 C-H 活化能力。然而，均相催化剂固有的不稳定性和催化剂回收困难限制了其发展。在此，我们报道了一种原子分散的 Ir 催化剂作为均相和多相催化之间的桥梁，该催化剂在低温（450°C）下用于正丁烷脱氢表现出优异的催化性能，正丁烷反应速率（8.8 mol·g·h）高，丁烯选择性（95.6%）好。重要的是，我们将 BDH 活性与纳米级到亚纳米级的 Ir 物种相关联，以揭示催化剂结构依赖性的本质。此外，我们将 Ir 单原子与 Pt 单原子和 Pd 单原子进行比较，以深入了解原子水平上的金属依赖性的本质。从实验和理论计算结果来看，孤立的 Ir 位有利于反应物的吸附/活化和产物的脱附。其显著的脱氢能力和适中的吸附行为是其具有优异催化活性和选择性的关键。
