“…For example, M. González-Castaño et al synthesized Ni catalyst supported on YMnO 3 perovskite via coprecipitation method, and the replacement of Mn 3+ by Ni 2+ atoms result in the formation of Mn 4+ species by way of a charge compensation mechanism, which attained the ability to exchange oxygen species, leading to the remarkable performance with TOFs = 20.1 s −1 at 400 °C and 60 L/(g•h). The presence of oxygen vacancies in the YMnO 3-x support effectively enhances the dissociative adsorption of CO 2 through easier redox interconversion, resulting in high activity and stable catalytic behavior without evidence of deactivation (González-Castaño et al, 2021). Similarly, the variable valence metals like Ce (Ren et al, 2021;, Fe (Thalinger et al, 2016b;Steiger et al, 2020), Ti (Tang et al, 2018;Do et al, 2020;Jiang et al, 2021), etc.…”