Zhou Huang, Zhao Yafei, Gan Jie, Xu Jie, Wang Ying, Lv Hongwei, Fang Shi, Wang Zhiyuan, Deng Ziliang, Wang Xiaoqian, Liu Peigen, Guo Wenxin, Mao Boyang, Wang Huijuan, Yao Tao, Hong Xun, Wei Shiqiang, Duan Xuezhi, Luo Jun, Wu Yuen
Hefei National Laboratory for Physical Sciences at the Microscale, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), School of Chemistry and Materials Science, and National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230026, China.
State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China.
J Am Chem Soc. 2020 Jul 22;142(29):12643-12650. doi: 10.1021/jacs.0c03415. Epub 2020 Jul 8.
The controllable synthesis of stable single-metal site catalysts with an expected coordination environment for high catalytic activity and selectivity is still challenging. Here, we propose a cation-exchange strategy for precise production of an edge-rich sulfur (S) and nitrogen (N) dual-decorated single-metal (M) site catalysts (M = Cu, Pt, Pd, etc.) library. Our strategy relies on the anionic frameworks of sulfides and N-rich polymer shell to generate abundant S and N defects during high-temperature annealing, further facilitating the stabilization of exchanged metal species with atomic dispersion and excellent accessibility. This process was traced by in situ transmission electron microscopy, during which no metal aggregates were observed. Both experiments and theoretical results reveal the precisely obtained S, N dual-decorated Cu sites exhibit a high activity and low reaction energy barrier in catalytic hydroxylation of benzene at room temperature. These findings provide a route to controllably produce stable single-metal site catalysts and an engineering approach for regulating the central metal to improve catalytic performance.
可控合成具有预期配位环境、高催化活性和选择性的稳定单金属位点催化剂仍然具有挑战性。在此，我们提出一种阳离子交换策略，用于精确制备富含边缘硫（S）和氮（N）的双修饰单金属（M）位点催化剂库（M = 铜、铂、钯等）。我们的策略依赖于硫化物的阴离子框架和富含氮的聚合物壳，在高温退火过程中产生大量的S和N缺陷，进一步促进交换后的金属物种以原子分散状态稳定存在并具有优异的可及性。该过程通过原位透射电子显微镜进行追踪，在此期间未观察到金属聚集体。实验和理论结果均表明，精确获得的S、N双修饰铜位点在室温下催化苯的羟基化反应中表现出高活性和低反应能垒。这些发现提供了一条可控生产稳定单金属位点催化剂的途径，以及一种通过调控中心金属来改善催化性能的工程方法。
