Synergistic Cu‐Zn/Fly Ash Catalysts for Intensified Sorption‐Enhanced CO ₂ Hydrogenation to CO Through the RWGS Reaction

Abstract The reverse water–gas shift (RWGS) reaction is one of the most direct approaches for converting CO 2 into CO, thereby enabling syngas production for downstream synthesis. Yet, its equilibrium limitations restrict CO yield under typical operating conditions, reducing overall process efficiency. Sorption‐enhanced reverse water–gas shift (SERWGS) is a promising intensified approach for syngas production while minimizing environmental impact, significantly increasing the yield of target products (CO) compared to conventional processes. Here, fly ash (FA) was investigated as a catalytic support to develop a novel Cu–Zn catalyst. Alkali/acid pretreatment on FA was very efficient in increasing specific surface area and porosity, promoting effective Cu/Zn dispersion. 15Cu‐7.5 Zn/FA Na–H catalyst prepared via deposition‐precipitation achieved the best performance (26.2% CO 2 conversion and 97.5% CO selectivity at 350 °C). Incorporating zeolitic adsorbents revealed that LTA‐4A provided superior intensification compared to FAU‐13X, enhancing the maximum CO 2 conversion by 131%, and effectively surpassing the thermodynamic limit of the conventional (non‐intensified) process, at 250 °C. These results highlight the combined role of optimized catalyst formulation and selective adsorbents in enhancing RWGS performance and provide key insights for the development of intensified RWGS processes that overcome thermodynamic limitations, offering valuable guidance for future research on sorption‐enhanced CO 2 conversion via catalytic hydrogenation.