Dry Reforming of Methane with CO2 using Efficient and Regenerable Bimetallic Supported Oxide Catalysts for Syngas Production
Abstract
Dry reforming of methane has been proposed as an effective method of converting methane and carbon dioxide, two of major greenhouse gases commonly found in biogas, into syngas; consisting of hydrogen and carbon monoxide. This ubiquitous feedstock can be utilized in various industries to produce fuels and chemicals. Expensive noble metal catalysts are often used in the process which is very energy intensive and require high temperatures. This necessitates the development of more cost-effective and regenerable catalysts that are resistant to deactivation by sintering and coking; and to minimize the use of precious metal catalysts. Bimetallic supported oxide catalysts have strong metal support interaction and synergetic effect between the two metal species, are created by leveraging the strong interaction between the metals and high energy faceted metal oxide support and the regenerative properties of the ABO3-type perovskite oxide.In this dissertation, the characteristics and effectiveness of various bimetallic metal alloy supported oxide catalysts for dry reforming of methane are studied. In the first chapter, Co-Ru alloy supported on the high-energy faceted TiO2 were employed for dry methane reforming of biogas. Secondly, the properties of Ni-Au/La2O3 catalysts created from the regenerable Au/LaNiO3 were investigated. And finally, a combination of in-situ and ex-situ characterization methods were employed to elucidate the exsolution properties of Ni-Ru alloy from the LaNi0.95Ru0.05O3 perovskites. This dissertation serves as a foundation for designing bimetallic supported oxide catalysts with unique properties. By tuning the type, composition, synthesis conditions, the characteristics of the catalysts such as nanoparticles size and phase can be controlled; thus, obtaining desirable properties such as enhanced activity, selectivity, and stability. The regenerability of the exsolved nanoparticles from the perovskite system also enables a more sustainable usage of the catalysts and minimizes the need for precious metals.