Ru nanoparticles supported on amorphous ZrO2 for CO2 methanation†
The influence of support materials and preparation methods on CO2 methanation activity was investigated using Ru nanoparticles supported on amorphous ZrO2 (am-ZrO2), crystalline ZrO2 (cr-ZrO2), and SiO2. Among them, Ru/am-ZrO2 showed high CO2 methanation activity. Of note, Ru/am-ZrO2 prepared by a selective deposition method was superior to that prepared by a wet impregnation method. This is because the Ru nanoparticles were highly dispersed when prepared by the selective deposition method, as evidenced by XPS. Interestingly, when NaOH solution was used as a pH adjuster for the selective deposition method, Ru/am-ZrO2 catalysts activated the formate species (one of the important reaction intermediates of CO2 methanation), leading to high CO2 conversion (73%, 250 °C).