Fan Yamei, Li Rongtan, Wang Beibei, Feng Xiaohui, Du Xiangze, Liu Chengxiang, Wang Fei, Liu Conghui, Dong Cui, Ning Yanxiao, Mu Rentao, Fu Qiang
Department of Chemical Physics, University of Science and Technology of China, Hefei, China.
State Key Laboratory of Catalysis, Chinese Academy of Sciences, Dalian Institute of Chemical Physics, Dalian, China.
Nat Commun. 2024 Apr 8;15(1):3046. doi: 10.1038/s41467-024-47397-z.
Sintering of active metal species often happens during catalytic reactions, which requires redispersion in a reactive atmosphere at elevated temperatures to recover the activity. Herein, we report a simple method to redisperse sintered Cu catalysts via O-HO treatment at room temperature. In-situ spectroscopic characterizations reveal that HO induces the formation of hydroxylated Cu species in humid O, pushing surface diffusion of Cu atoms at room temperature. Further, surface OH groups formed on most hydroxylable support surfaces such as γ-AlO, SiO, and CeO in the humid atmosphere help to pull the mobile Cu species and enhance Cu redispersion. Both pushing and pulling effects of gaseous HO promote the structural transformation of Cu aggregates into highly dispersed Cu species at room temperature, which exhibit enhanced activity in reverse water gas shift and preferential oxidation of carbon monoxide reactions. These findings highlight the important role of HO in the dynamic structure evolution of supported metal nanocatalysts and lay the foundation for the regeneration of sintered catalysts under mild conditions.
活性金属物种的烧结在催化反应过程中经常发生，这需要在高温下于反应性气氛中进行再分散以恢复活性。在此，我们报道了一种在室温下通过O-HO处理使烧结的铜催化剂再分散的简单方法。原位光谱表征表明，HO在潮湿的O中诱导形成羟基化的铜物种，推动铜原子在室温下的表面扩散。此外，在潮湿气氛中，在大多数可羟基化的载体表面（如γ-AlO、SiO和CeO）上形成的表面OH基团有助于拉动可移动的铜物种并增强铜的再分散。气态HO的推动和拉动作用都促进了铜聚集体在室温下向高度分散的铜物种的结构转变，这些铜物种在逆水煤气变换和一氧化碳优先氧化反应中表现出增强的活性。这些发现突出了HO在负载型金属纳米催化剂动态结构演变中的重要作用，并为在温和条件下烧结催化剂的再生奠定了基础。
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