Preparation of Ni‐M (M: La, Co, Ce, and Fe) catalysts supported on mesoporous nanocrystalline γ‐Al2O3 for CO2 methanation

Abstract

In this study, the effect of adding second metals (La, Co, Ce, and Fe) to the nickel catalysts supported on mesoporous nanocrystalline γ‐Al2O3 in CO2 methanation was investigated. The co‐impregnation method was implemented to synthesize the bimetallic catalysts and the X‐ray diffraction, nitrogen adsorption/desorption, and temperature‐programmed reduction methods were employed for the catalyst characterization. According to the catalytic results, the addition of the second metals to the nickel‐based catalyst increased the catalyst reducibility and decreased the specific surface area from 143.3 to 107.9 m2/g and nickel crystallite size from 18.9 to 5.1 nm. Furthermore, the addition of 10 wt % lanthanum to the 20 wt % Ni/γ‐Al2O3 increased the CO2 conversion from 42% to 80.3% in methanation of carbon dioxide. Novelty or Significance: The study is focused on the preparation and evaluation of the La, Co, Ce, and Fe‐promoted Ni/Al2O3 nanocatalysts with mesoporous structure in CO2 methanation reaction. The results confirmed that the incorporation of these compounds in catalyst composition improved the reducibility of the nickel catalyst and decreased the BET area and Ni crystallite size and affected the CO2 conversion and CH4 selectivity. Among these metal oxides, the addition of La2O3 to the Ni/Al2O3 catalyst had the highest effect on the activity and selectivity of the Ni/Al2O3 catalyst. © 2018 American Institute of Chemical Engineers Environ Prog, 38: 118–126, 2019