Lin Heyun, Zhang Wenzhe, Shen Huachen, Yu Hailing, An Yunlei, Lin Tiejun, Zhong Liangshu
Key Laboratory of Low-Carbon Conversion Science and Engineering, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai, 201210, China.
University of Chinese Academy of Sciences, Beijing 100049, P. R. China.
Nanoscale. 2024 Mar 21;16(12):6151-6162. doi: 10.1039/d3nr06208b.
The catalytic behavior of CO hydrogenation can be modulated by metal-support interactions, while the role of the support remains elusive. Herein, we demonstrate that the presence of strong metal-support interactions (SMSI) depends strongly on the crystal phase of TiO (rutile or anatase) and the treatment conditions for the TiO support, which could critically control the activity and selectivity of Ru-based nanocatalysts for CO hydrogenation. High CO conversion and olefin selectivity were observed for Ru/rutile-TiO (Ru/r-TiO), while catalysts supported by anatase (a-TiO) showed almost no activity. Characterization confirmed that the SMSI effect could be neglected for Ru/r-TiO, while it is dominant on Ru/a-TiO after reduction at 300 °C, resulting in the coverage of Ru nanoparticles by TiO overlayers. Such SMSI could be suppressed by H treatment of the a-TiO support and the catalytic activity of the as-obtained Ru/a-TiO(H) can be greatly elevated from almost inactive to >50% CO conversion with >60% olefin selectivity. Further results indicated that the surface reducibility of the TiO support determines the SMSI state and catalytic performance of Ru/TiO in the CO hydrogenation reaction. This work offers an effective strategy to design efficient catalysts for the FTO reaction by regulating the crystal phase of the support.
CO加氢的催化行为可通过金属-载体相互作用进行调控，而载体的作用仍不明确。在此，我们证明强金属-载体相互作用（SMSI）的存在强烈依赖于TiO的晶相（金红石型或锐钛矿型）以及TiO载体的处理条件，这能够严格控制Ru基纳米催化剂用于CO加氢的活性和选择性。对于Ru/金红石型TiO（Ru/r-TiO），观察到高CO转化率和烯烃选择性，而由锐钛矿型（a-TiO）负载的催化剂几乎没有活性。表征证实，对于Ru/r-TiO，SMSI效应可忽略不计，而在300℃还原后，它在Ru/a-TiO上占主导，导致Ru纳米颗粒被TiO覆盖层覆盖。通过对a-TiO载体进行H处理可抑制这种SMSI，所得Ru/a-TiO(H)的催化活性可从几乎无活性大幅提高至CO转化率>50%且烯烃选择性>60%。进一步的结果表明，TiO载体的表面还原性决定了Ru/TiO在CO加氢反应中的SMSI状态和催化性能。这项工作通过调控载体的晶相，为设计用于费托反应的高效催化剂提供了一种有效策略。
