CeO 2 -Modified NiIn-CaO Catalysts for Lowering the Temperature of Integrated CO 2 Capture and Reverse Water–Gas Shift Reaction: Performance and Mechanism

Lowering the temperature of the integrated CO2 capture and reverse water–gas shift (ICCU-RWGS, typically above 650 °C) reaction presents great potential for addressing the current challenges of low CO2 conversion, a lack of carbon balance, and severe sintering. Herein, we successfully achieved the ICCU-RWGS reaction at 550 °C using CeO2-modified NiIn-CaO catalysts. Systematic characterizations reveal that the incorporation of CeO2 can modify the electronic structure of NiIn intermetallic compounds (IMCs), which weakens H2 adsorption and dissociation relative to that of CO, thereby preventing further hydrogenation of CO to CH4. Additionally, CeO2 not only exhibits a strong interaction with NiIn IMCs to stabilize particles but also serves as a physical barrier to inhibit structural degradation, thereby guaranteeing the high stability of the catalyst. Consequently, CO2 conversion, CO selectivity, and carbon balance during the entire 50-cycle test remained stable at 94.6, 100, and 98.0%, respectively, and the CO2 adsorption capacity decreased by only 21.5%.