Enhanced low-temperature CO2 methanation over Ni/ ZrO2-Al2O3 catalyst: Effect of Al addition on catalytic performance and reaction mechanism
Hao Fu, Shaohui Sun, Honglei Lian
Abstract
It is desirable but challenging to obtain high CO 2 conversion in low-temperature CO 2 methanation and elucidate the reaction mechanism on nickel-based catalysts. In this work, we incorporated Al into Ni/ZrO 2 to form nickel-based catalysts supported by ZrO 2 -Al 2 O 3 composite support. The addition of the appropriate amount of Al increased the dispersion of metal Ni on the catalyst surface, promoted the activation and dissociation of H 2 , and thus significantly improved the activity of CO 2 methanation at low-temperature (< 300 °C). The CO 2 methanation on nickel-based catalysts supported on ZrO 2 -Al 2 O 3 composite supports all follow the formate reaction pathway. Since adding Al removes the ability of ZrO 2 to activate H 2 , the active sites of the catalyst change from the surrounding support to the support-Ni interface, which improves the efficiency of the hydrogenation reaction of the active intermediate.