(533a) In-Situ CO2 Capture-Conversion in Methane Dry Reforming for Direct Synthesis of Hydrogen over Bifunctional Structured Ce1-XCoxnio/Ca perovskites-Type Oxides Monoliths

The need for CO₂ utilization is rising on account of its high abatement cost and low market value. Bifunctional materials (BFMs) comprised of adsorbents and catalysts have shown promise as a pathway to capture CO₂ at high temperature and subsequently utilize the contaminant as a feedstock. ^{[1, 2]} However, previous efforts in the development of BFMs have been limited, with efforts put forth towards structuring such materials into facile contactors being narrower still. In this study, we therefore expanded the use of 3D printing technology to previously unexplored BFMs – comprised of a CaO adsorbent and trimetallic Ni/Co/Ce perovskite catalysts – for the application of combined CO₂ capture and methane reforming. Three honeycomb monoliths comprised of 50% adsorbent and 50% catalyst with varied ceria/cobalt ratio were 3D printed to assess the role of cobalt on catalytic properties and overall performance. The samples were vigorously characterized using X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), N₂ Physisorption, X-ray photoelectron spectroscopy (XPS), H₂-TPR, In-Situ CO₂ adsorption/desorption XRD, and NH₃-TPD. From these, it was determined that the ceria/cobalt ratio did not influence crystallinity, textural properties, CO₂ adsorption/desorption reversibility, or metallic dispersion, but did cause reductions in acidity, CO₂/CaO bond strength and reducibility at elevated cobalt loading. Assessing the samples via combined CO₂ capture and methane reforming from 500-700 °C revealed that such differences in physiochemical properties lowers H₂ and CO yield at higher cobalt loading, leading to the best performance in the Ce_0.75Co_0.25NiO/Ca sample that achieved 52% CO₂ conversion, 94% CH₄ conversion, 61% H₂ yield, and 2.30 H₂/CO ratio at 700 °C. The stability of this sample was assessed across five adsorption (T = 600 °C)/reaction (T = 700 °C) cycles, showing only marginal losses in H₂/CO yield. Thusly, these findings successfully expand the use of 3D printing to unexplored perovskite BFMs and demonstrate an important proof-of-concept for their use in combined CO₂ capture and utilization for methane reforming processes.