Fundamental Aspects of Enhancing Low-Temperature CO₂Splitting to CO on a Double La₂NiFeO₆Perovskite

This paper addresses the synergistic effect of binary Ni-Fe sites in double La₂NiFeO₆perovskite on low-temperature CO₂conversion to CO in the reverse water-gas shift-chemical looping process. Experimental investigations and DFT calculations proved that, for the reduction of perovskite, the Ni-site facilitates the formation of surface oxygen vacancies and the adsorption of hydrogen with agile lattice oxygen mobility. Thus, incorporating Ni can improve the reducibility at low temperature. The Fe-site prevents strong adsorption of the CO₂molecules on the La-site to facilitate its direct dissociation into CO molecules, and thereby CO₂conversion increases with Fe loading. Consequently, La₂NiFeO₆can satisfy both high reducibility and CO₂splitting activity by the synergy of binary Ni-Fe sites. It presents an average CO productivity of 2.14 mmol/g_catand a maximum CO production rate of 1.69 mmol/g_cat·min at 700 °C, more than 4.7-fold and 10-fold higher than each single LaNiO₃and LaFeO₃perovskites, respectively.