Tuning A-site chemistry in AZrO3 perovskites for integrated CO2 capture and methanation

The Integrated Carbon Capture and Utilization (ICCU) strategy is gaining growing interest as a way to mitigate CO2 emissions and transforming them into useful chemicals in a single reactor. The ICCU approach relies on Dual-Function Materials (DFMs), which combine sorption and catalytic conversion functionalities in one single unit. Here, we systematically explore the role of different alkaline and alkaline-earth cations in determining the microstructural, chemical and catalytic properties of Ru-loaded zirconate perovskites, with alkali elements in the A site, AZrO3, highlighting their impact on performance indicators such as CO2 capture capacity, methanation rate and cyclic stability. The study provides evidence of zirconates-based DFMs being stable and efficient, particularly for Ru/SrZrO3 (CO2 capture: 170 mu mol g- 1, CH4 production: 111 mu mol g- 1). Considering that such DFMs are characterized by surface area values one order of magnitude lower than conventional Al2O3-based materials, the Ru/AZrO3 DFMs possess enhanced surface-specific activity compared to state-of-the-art DFMs, underscoring the importance of future microstructural optimization and providing guidance for the rational design of such materials.