Optimizing crystallinity of La2O2CO3 to boost reverse water-gas shift reaction performance over Co-based supported catalysts

Abstract

Reverse water-gas shift (RWGS) reaction has become an important strategy to couple application of carbon resources and hydrogen energy. However, Co-based supported catalysts in RWGS reaction consistently experience deactivation under high-temperature operation, predominantly caused by carbon deposition and metal sintering, which present major barriers to the commercial deployment. Here, crystallinity for La₂O₂CO₃ supports were modulated to govern the metal-support interaction and CO₂ adsorption performance on Co-based supported catalysts, thereby optimizing RWGS reaction performance. Despite of poorly crystallized La₂O₂CO₃-1 fostered a stronger interaction with Co species, which detrimentally compromised CO₂ adsorption capacity and inherent anti-coking functionality of La₂O₂CO₃ themselves. In contrast, employing well-crystallized La₂O₂CO₃-2 as the support yielded the Co/La₂O₂CO₃-2 catalyst, exhibiting superior CO₂ adsorption, exceptional resistance to carbon deposition, outstanding activity, high CO selectivity, and remarkable stability—maintaining consistent CO₂ conversion and selectivity for over 100 h at 600 °C. This crystallinity-driven strategy effectively balances the Co-La₂O₂CO₃ interaction, presenting a novel way to boost RWGS reaction performance over Co-based supported catalysts.