Sani, Luqman Abdullahi, Bai, Haolong, Xu, Zifu, Fu, Liangliang, Sun, Yining, Huang, Xiaorui, Gao, He, Liu, Xuejing, Bai, Dingrong, Zhang, Zhanguo, Su, Fabing, Liu, Jiao, and Xu, Guangwen
Ni/Al 2 O 3 catalysts (noted as Ni/Al-350, Ni/Al-500, and Ni/Al-700, respectively) were synthesized by a facile solution combustion method but at different combustion temperatures (350 °C, 500 °C, and 700 °C, respectively). For comparison, Ni/Al 2 O 3 (noted as Ni/Al-100) was also prepared by the impregnation method and applied in the methanation reaction. The Ni/Al 2 O 3 synthesized at the combustion temperature of 350 °C showed better performance than the others at higher combustion temperatures, and the activity for CO 2 methanation followed an order of Ni/Al-350 > Ni/Al-500 > Ni/Al-700 > Ni/Al-100. The increase in the combustion temperature decreased active sites for the H 2 and CO 2 adsorption, which could be associated with the reduced Ni dispersion and basic sites, thus lowering its activity and increasing its carbon deposition rate. [Display omitted] • Combustion temperature affects the interaction between Ni and support. • Combustion temperature rising leads to the nickel agglomeration. • Combustion temperature rising decrease the surface oxygen vacancy concentration. • 350 °C was the proper combustion temperature for Ni/Al 2 O 3 for CO 2 methanation. [ABSTRACT FROM AUTHOR]