Density functional theory study of the mechanism of CO methanation on Ni4/t-ZrO2 catalysts: Roles of surface oxygen vacancies and hydroxyl groups

The formation mechanism of CO methanation on Ni/t-ZrO2 catalysts and the rate limiting step (RDS) on Ni4/t-ZrO2(101), Ni4/VO-t-ZrO2(101) and Ni4/H-t-ZrO2(101) surface are depicted in this picture. Compared with the energy barrier of CH3OH formation, both the selectivity and activity of CO methanation are improved the oxygen vacancies and hydroxyl groups are beneficial for CH4 formation.241