Highly active Ni/Al2O3 catalyst for CO2 methanation by the decomposition of Ni-MOF@Al2O3 precursor via cold plasma.

[Display omitted] • Low temperature plasma was adopt in the fabrication of nano Ni/Al 2 O 3 -P Catalysts. • The new approach improves the Ni dispersion and suppresses the formation of spinel. • The formation of the Ni-Al 2 O 3 interfaces was controlled by adjusting the Ni loading. • Low temperature performance of CO 2 methanation is improved significantly. In this work, a novel Ni/Al 2 O 3 -P catalyst for CO 2 methanation was prepared via an oxygen plasma decomposition of the Ni-MOF@Al 2 O 3 core–shell precursor. The obtained catalyst showed a higher Ni dispersion (26.5%) and contained less NiAl 2 O 4 spinel when compared with the Ni/Al 2 O 3 prepared by the traditional method. The Ni/Al 2 O 3 -P catalyst showed significantly enhanced efficiency toward CO 2 methanation as compared with those catalysts with a similar nickel loading but are prepared using the traditional method. For example, the space time yield of methane (STY CH4) of the Ni/Al 2 O 3 -P catalyst was as high as 21103.6 mg∙g Ni -1∙h−1 at 400 °C and GHSV as 12000 ml∙g−1∙h−1, which is 3.4 times higher than that of the reported catalyst (6190.5 mg∙g Ni -1∙h−1) with a similar nickel loading under similar reaction conditions. Moreover, Density Functional Theory (DFT) studies together with the CO 2 -TPD results revealed that both nickel surface and Ni-Al 2 O 3 interface could activate CO 2 , while the NiAl 2 O 4 surface could not. [ABSTRACT FROM AUTHOR]