Nanostructured Metal Oxides for Desulfurization and Heterogeneous Catalysis

Abstract

Metal oxides have broad applications in industry and manufacturing. In order to maximize the performance of the metal oxides for targeted applications, it is critical that the preparation process is tailored and optimized. This thesis demonstrates the design, synthesis, characterization, and optimization of two types of porous metal oxides for applications for the removal of H2S in natural gas processing and for high temperature heterogenous catalysis.During natural gas production, the use of metal oxides as solid sorbents in the tail gas treatment unit is economically and operationally beneficial compared to the commercialized liquid sorption process. In the first part of this thesis, a type of porous mixed metal oxide (MMO) sorbent with active CuO is prepared through coprecipitation, and is demonstrated to have superior H2S sorption capacity. This sorbent can be recycled in a continuous adsorption–desorption process with stable performance. In addition, a facile pelletization approach was established, and the regeneration conditions of the pellets were optimized. This study demonstrated good reliability and applicability of this sorbent material in simulated testing conditions. The second part of this thesis describes the preparation of MMOs through nanocasting metal–organic frameworks (MOFs). The metal oxo clusters in MOFs are a source of metal species for MMOs, and the casting organometallic precursors provide another component. Nanocasting largely retains the morphological and structural information of the MOF template in the final MMOs, and provides well-defined MOF-derived catalytically active centers with enhanced thermal stability suitable for high temperature catalysis.