Ru/TiO2 Catalysts with Size-Dependent Metal/Support Interaction for Tunable Reactivity in Fischer–Tropsch Synthesis

• Published in: ACS catalysis 2020-11, Vol.10 (21), p.12967-12975
• Main Authors: Zhang, Yaru, Su, Xiong, Li, Lin, Qi, Haifeng, Yang, Chongya, Liu, Wei, Pan, Xiaoli, Liu, Xiaoyan, Yang, Xiaofeng, Huang, Yanqiang, Zhang, Tao
• Format: Article
• Language: English
• ISSN: 2155-5435; 2155-5435
• DOI: 10.1021/acscatal.0c02780

The Ru/TiO2 catalyst serves as a representative metal/support interaction system with tunable reactivity in catalytic processes. Herein, by varying the metal loadings of Ru from 0.5 to 4 wt % to regulate the size of Ru on support, the catalytic performances of Ru/TiO2 catalysts in Fischer–Tropsch synthesis (FTS) can be further refined. An improved FTS activity is acquired when metal size increases, while long carbon-chain products (C5+ hydrocarbons) prefer to be generated from the small-sized Ru catalyst. With intensive characterizations, it is indicated that the coating of TiO x on Ru greatly depends on the size of Ru, with the TiO x overlayer being enhanced on small Ru metal particles. This size-dependent metal/support interaction on Ru/TiO x therefore leads to a varied reduction degree of Ru, which possesses an alterable capability toward CH x transformation on Ru. As a result, the small-sized Ru/TiO x catalyst shows a preference toward the chain growth in FTS by suppressing the competitive methanation on Ru/TiO x . Our results demonstrate that the size-dependent metal/support interaction plays an important role on determining the catalytic performance of Ru/TiO x in FTS, and it can be used as an effective method to tune the reactivity of metal nanoparticles in catalytic processes.