(650c) Dual Functional Perovskite-Based Catalysts for CO2 Sorption and Syngas Production

The capture of CO₂ from large point sources and subsequent conversion to useful products is seen as a potential solution to alleviate the effects anthropogenic climate change. Dual Functional Materials (DFM) allow for the capture of carbon dioxide by combining sorption of CO₂ on the surface nd conversion over to catalytic sites to react with reducing gases, often H₂, CH₄ or C₂H₆. Perovskite oxides have noted tunable redox and catalytic properties by introduction of stoichiometric defects and substitution of metals. In our previous work we have discussed the use of Ni substituted LaFeO₃ type perovskites tailored for catalysis of methane-carbon dioxide reforming. In this work we discuss CO₂ capture and conversion with Sr based perovskites with Ni substitution as DFMs. We synthesized Ni supported on SrZrO₃ and SrTiO₃ type perovskites and tested them for methane dry reforming in co-fed and looping modes and CO₂ reduction by CH₄ and H₂. Strontium or other alkali metals in perovskites as strong basic sites that can sorb CO₂ in the form of surface carbonate species. Nickel atoms are the sites for catalytic activity where adsorbed CO₂ reacted with methane/hydrogen. We show that stoichiometric defects altered the nature of basic sites available with A-site deficient samples having more of the weakly basic sites.