Exploration of Indium Alumina As a Heterogenous Lewis Acid Catalyst for Propylene Oligomerization and Hydrogenation

Within the U.S., there is a push to transition the production of transportation fuels from crude oil to natural gas liquids. Natural gas liquids (NGLs) serve as a bridge fuel to produce diesel fuel since NGLs produce less CO₂ emissions compared to petroleum feedstocks. Shale deposits yield natural gas liquids that provide a long-lasting energy source and feedstocks to produce high-value commodity chemicals. Single-site indium(III) alumina-supported catalysts will catalyze light hydrocarbon reactions to produce heavy hydrocarbon fuels such as diesel and gasoline. Literature suggests that indium is not known to perform these reactions. We synthesized indium-alumina catalysts using incipient wetness impregnation and tested various catalyst metal loadings. We also tested varying reactor conditions including gas flow rates and temperatures. We analyzed gas chromatography data to compare the conversion and product selectivity of indium-alumina and pure alumina catalysts. X-ray absorption spectroscopy suggests that indium-alumina contains indium single-sites. This study compares the catalytic properties of indium-alumina and alumina catalysts to determine the viability of using indium catalysts for light hydrocarbon reactions. Indium-alumina has proven to be a more effective catalyst for propylene oligomerization and hydrogenation than pure alumina. Establishing indium-alumina as a catalyst capable of performing hydrocarbon chemistry will deepen our understanding of the mechanisms that govern these reactions. Thus, allowing scientists to produce more efficient catalysts capable of manufacturing transportation fuels and commodity chemicals.