Smaller nano-sizes typically result in supported catalysts with abundant interfacial and intrinsic oxygen vacancies for better adsorption and activation of small molecules, including CO2, leading to improved efficiency of CO2 methanation. Here, Ni/CeO2-S with the smaller nano-size of around 4.2 nm is used to catalyze CO2 methanation, which exhibits significantly enhanced activity compared to larger nano-sized Ni/CeO2-L catalyst, even surpassing the most majority of previously reported catalysts using CeO2 as the support or Ni as the active metal. The coexistence of interfacial defects and intrinsic oxygen vacancies allows for enhanced adsorption and activation of CO2 molecules as well as H spillover, resulting in such improved CO2 methanation. In-situ DRIFTS demonstrate a nearly sole Formate pathway on Ni/CeO2-S for efficient CO2 hydrogenation. This research provides valuable insights into the reaction mechanism over a small nanosize supported catalyst.

中文翻译：

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丰富的界面和本征氧空位，可实现小的镍/氧化铈纳米晶高效的 CO2 甲烷化


较小的纳米尺寸通常会导致负载型催化剂具有丰富的界面和本征氧空位，以更好地吸附和活化小分子（包括 CO2），从而提高 CO2 甲烷化的效率。在这里，具有较小纳米尺寸（约 4.2 nm）的 Ni/CeO2-S 用于催化 CO2 甲烷化，与较大的纳米 Ni/CeO2-L 催化剂相比，其活性显着增强，甚至超过了以前报道的大多数使用 CeO2 作为载体或 Ni 作为活性金属的催化剂。界面缺陷和本征氧空位的共存可以增强 CO2 分子的吸附和活化以及 H 溢出，从而改善 CO2 甲烷化。原位 DRIFTS 证明 Ni/CeO2-S 上几乎唯一的甲酸盐途径可实现高效的 CO2 加氢。这项研究为小纳米负载型催化剂的反应机理提供了有价值的见解。