Liu Yanduo, Chen Yihong, Jiang Wenbin, Kong Tingting, Camargo Pedro H C, Gao Chao, Xiong Yujie
School of Chemistry and Materials Science, University of Science and Technology of China, Hefei, Anhui 230026, China.
Institute of Energy Hefei Comprehensive National Science Center, Hefei, Anhui 230031, China.
Research (Wash D C). 2022 Nov 7;2022:9831340. doi: 10.34133/2022/9831340. eCollection 2022.
Photocatalytic nonoxidative coupling of CH to multicarbon (C) hydrocarbons (e.g., CH) and H under ambient conditions provides a promising energy-conserving approach for utilization of carbon resource. However, as the methyl intermediates prefer to undergo self-coupling to produce ethane, it is a challenging task to control the selective conversion of CH to higher value-added CH. Herein, we adopt a synergistic catalysis strategy by integrating Pd-Zn active sites on visible light-responsive defective WO nanosheets for synergizing the adsorption, activation, and dehydrogenation processes in CH to CH conversion. Benefiting from the synergy, our model catalyst achieves a remarkable C compounds yield of 31.85 mol·g·h with an exceptionally high CH selectivity of 75.3% and a stoichiometric H evolution. In situ spectroscopic studies reveal that the Zn sites promote the adsorption and activation of CH molecules to generate methyl and methoxy intermediates with the assistance of lattice oxygen, while the Pd sites facilitate the dehydrogenation of methoxy to methylene radicals for producing CH and suppress overoxidation. This work demonstrates a strategy for designing efficient photocatalysts toward selective coupling of CH to higher value-added chemicals and highlights the importance of synergistic active sites to the synergy of key steps in catalytic reactions.
在环境条件下,光催化CH与多碳(C)烃(如CH)和H的非氧化偶联为碳资源的利用提供了一种很有前景的节能方法。然而,由于甲基中间体倾向于进行自偶联以生成乙烷,将CH选择性转化为高附加值的CH是一项具有挑战性的任务。在此,我们采用一种协同催化策略,通过在可见光响应的缺陷WO纳米片上整合Pd-Zn活性位点,以协同CH转化为CH过程中的吸附、活化和脱氢过程。得益于这种协同作用,我们的模型催化剂实现了31.85 mol·g·h的显著C化合物产率,具有75.3%的超高CH选择性和化学计量的H析出。原位光谱研究表明,Zn位点促进CH分子的吸附和活化,在晶格氧的协助下生成甲基和甲氧基中间体,而Pd位点促进甲氧基脱氢生成亚甲基自由基以生成CH并抑制过度氧化。这项工作展示了一种设计高效光催化剂以实现CH选择性偶联生成高附加值化学品的策略,并突出了协同活性位点对催化反应关键步骤协同作用的重要性。