甲烷化
锐钛矿
金红石
催化作用
化学
无机化学
氢
烯酮
氢溢流
化学工程
光催化
有机化学
工程类
作者
Davina Messou,Vincent Bernardin,Frédéric C. Meunier,Marta Borges Ordoño,Atsushi Urakawa,Bruno Machado,Vincent Collière,Régis Philippe,Philippe Serp,Carole Le Berre
标识
DOI:10.1016/j.jcat.2021.04.004
摘要
The catalytic performances of TiO2-supported Ni catalysts for the methanation of CO2 have been investigated using different crystalline phases of TiO2 (rutile and anatase). The catalytic activity of Ni depends appreciably on the nature of the support. The rate for CO2 hydrogenation decreases in the order of 10Ni/TiO2-rutile ≫ 10Ni/TiO2-anatase. The use of a mixture of catalysts containing 70% 10Ni/TiO2-anatase + 30% 10Ni/TiO2-rutile allows for a significant increase of the reaction rate related to 100% 10Ni/TiO2-rutile. Importantly, it has been demonstrated that the two catalysts do not need to be in direct contact for the synergetic effect to occur. DRIFTS operando analysis during the methanation reaction shows that adsorbed CO accumulates on Ni/TiO2-anatase and not on Ni/TiO2-rutile, and that the role of the Ni/TiO2-rutile is to assist the hydrogenation of this adsorbed CO on the Ni/TiO2-anatase. Increased CO2 methanation is also observed by adding Ni-free TiO2-anatase to 10Ni/TiO2-rutile, indicating that COx hydrogenation can also occur on bare TiO2-anatase if activated hydrogen can be supplied by another source. H2-TPD analyses and catalytic tests performed after dilution of the catalysts have shown that hydrogen spillover (mediated by surface or gas-phase species) is at the origin of the synergy observed between the two catalysts for the Sabatier reaction.
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