Surface chemistry and dynamics of Dual Functional Materials prepared by green mechanochemistry under CO2 capture and methanation: correlating the reactivity with the structure and the synthesis

We are studying Dual Functional Materials (DFMs) for the CO2 capture and conversion by methanation. These materials are used in the Integrated Carbon Capture and Utilisation process (ICCU-MET) in which the same material is used to capture CO2 and catalytically valorise it to useful products such as methane. We are preparing DFMs based on Ru and Na dispersed on Al2O3 by a green mechanochemical method, using rapid solventless synthesis to achieve high catalytic performances. The study was conducted following a full factorial experimental design to efficiently understand the effect of the milling intensity and the choice of precursors on the DFMs performances. We have obtained several samples with different reactivity and clear trends between the CO2 capture capacity, the CH4 production and the milling intensity. With the NAP-XPS experiment proposed here, we will solve two problems: (i) we will gather direct information about the surface of DFMs under relevant reaction conditions; (ii) we will be able to relate the milling parameters with the surface composition and find the structure-activity relationship.