CO2 methanation over TiO2–Al2O3 binary oxides supported Ru catalysts

TiO2 modified Al2O3 binary oxide was prepared by a wet-impregnation method and used as the support for ruthenium catalyst. The catalytic performance of Ru/TiO2–Al2O3 catalyst in CO2 methanation reaction was investigated. Compared with Ru/Al2O3 catalyst, the Ru/TiO2–Al2O3 catalytic system exhibited a much higher activity in CO2 methanation reaction. The reaction rate over Ru/TiO2–Al2O3 was 0.59 mol CO2·(g Ru)− 1·h− 1, 3.1 times higher than that on Ru/Al2O3 [0.19 mol CO2·(g Ru)− 1·h− 1]. The effect of TiO2 content and TiO2–Al2O3 calcination temperature on catalytic performance was addressed. The corresponding structures of each catalyst were characterized by means of H2-TPR, XRD, and TEM. Results indicated that the averaged particle size of the Ru on TiO2–Al2O3 support is 2.8 nm, smaller than that on Al2O3 support of 4.3 nm. Therefore, we conclude that the improved activity over Ru/TiO2–Al2O3 catalyst is originated from the smaller particle size of ruthenium resulting from a strong interaction between Ru and the rutile-TiO2 support, which hindered the aggregation of Ru nano-particles.

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