Integrated CO2 capture and utilisation: exploring dual-functional materials and molten salt media

This study investigates dual-functional materials (DFMs) for ICCU-dry reforming of methane (ICCU-DRM) and ICCU-reverse water-gas shift (ICCU-RWGS) reactions. <br><br>A Ni0.05/CaO0.95 DFM was evaluated under various simulated flue gas conditions (10 % CO2/N2; 10 % CO2 + 6% H2O/N2; 10 % CO2 + 6.7 % O2/N2; 10 % CO2 + 6 % H2O + 6.7 % O2/N2) at 650 ℃ and atmospheric pressure.

Each cycle involved 30 min CO2 capture, 5 min N2 purge, and CH4 conversion with 10 % CH4/N2. Characterizations (XRD, in-situ DRIFTS, CH4-TPR, SEM, EDX, FIB-SEM, BET, XPS) revealed that O2 and H2O severely degraded performance by oxidizing Ni and causing CaO/Ni volumetric expansion, forming dense shells that hindered NiO reduction.<br><br>Decoupled experiments using Ni/SiO2 catalysts and sol-gel CaO sorbents demonstrated that Ni activated adsorbed CO2 to react with coke from CH₄ decomposition, with catalyst-sorbent contact critical for the reverse Boudouard reaction.