Mechanistic approach of CO2-Storage and Regeneration process using Ni-modified unsupported model catalyst

DIANA PELTZER, LAURA CORNAGLIA; M. CORTÉS-REYES, C. HERRERA, M.A. LARRUBIA, L.J. ALEMANY

Puerto Vallarta

Congreso; XXVII CONGRESO IBEROAMERICANO DE CATÁLISIS; 2020

This work presents a mechanistic approach of a CO2-Storage and Regeneration process using unsupported Ni-Ba as model catalyst. The material was synthesized by coprecipitation, adding colloidal SiO2 as surface promoter, and calcined at 800 ºC. The solid was characterized by N2 sorptometry at 77K and XRD. The mechanistic study was performed by isotopic and non-isotopic catalytic tests of CO2 storage and regeneration steps with CH4, using Transient Response Method (TRM).The catalyst presented good textural properties, and the formation of an isostructural [NiBa]O mixed cubic structure (with an average crystal size of 15 nm) was detected by XRD. Non-isotopic tests confirmed the CO2 adsorption and reduction with CO generation during the storage step. Moreover, H2 and CO were produced during the regeneration step, through in situ dry reforming of methane and catalytic CH4 decomposition. The isotopic experiments with 13CO2 allowed distinguishing the different C sources and the predominant reactions in each step. According to this mechanistic approach, the CO2 reduction during the storage step would oxidize the Ni present in the catalyst, while the H2 generated during the methane step would favor its reduction. The good redox properties allow the material working on a chemical loop, catalyzing the reactions in every step.