SusChEM: Dispersed Metal Oxides for the Sustainable Production of Propylene

University Of Wisconsin-Madison, Madison WI

Investigators

Abstract

1605101 Hermans, Ive The study aims to develop an efficient catalyst for the Oxidative De-Hydrogenation of Propane (ODHP) to propylene as an alternative to conventional processes for supplying the huge industrial demand for propylene as a chemical intermediate in the production of a wide range of value-added products. The work is motivated by substantial opportunities for energy savings combined with effective utilization of shale gas resources to maintain competitiveness of the U.S. Chemical Industry. ODHP offers a thermodynamically favored route to the production of propylene versus current technologies assuming reaction selectivity can be controlled to avoid wasteful over-combustion. Catalysts based on supported vanadium oxide materials have been widely investigated, and it is known that both the dispersion of the vanadium oxide and the choice of support material play important roles in controlling the activity and selectivity. Selectivity for propylene production is favored by two-dimensional (2D) vanadia species, and the investigator's group has recently obtained loadings of such species on silica far above levels previously believed to represent a maximum dispersion limit. The high dispersion was found to be associated with a sodium promoter in the silica, leading to a working hypothesis that sodium catalyzes the formation of the dispersed 2D vanadia, relative to the nucleation rate of less active and selective 3D particles. The investigator has also found further enhancements in ODHP rates and propylene selectivity by co-immobilizing tantalum oxide and vanadium oxide on silica as catalyzed by sodium. The study will seek further enhancements in ODHP catalyst activity and selectivity via two thrusts. The first utilizes CVD techniques and additional investigation of the mechanism by which sodium promotes vanadia dispersion (including an investigation of post-synthesis removal of sodium to increase activity). The second thrust will extend the co-immobilization studies to a family of ternary oxides (V-M/SiO2) where M will consist of tantalum, zirconium, and aluminum, amongst others. The investigator has a broad range of characterization tools at his disposal to achieve detailed insight into the chemistry and structure of these materials via collaboration with ETH Zurich and Argonne National Laboratory. The study will broadly promote education and outreach related to STEM areas while laying fundamental groundwork for new catalysts and catalytic processes responsive to the changing landscape of the chemical and petroleum industries.