Ru nanoparticles supported on amorphous ZrO2 for CO2 methanation

Abstract

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).