The recent development of solid oxide fuel cells (SOFC) capable of using
liquefied petroleum gas (LPG) as a feedstock has created a viable high energy density
technology for replacing the diesel generators and batteries used to create power in
remote or mobile applications. Due to the unsurpassed volumetric energy density of
liquid hydrocarbon fuels and the existing infrastructure for their distribution, it is
preferable to transport and store diesel and jet fuel and catalytically crack it on-site to
LPG. The ideal cracking catalyst must be capable of operating without excessively
coking or being poisoned by sulfur present in the feedstock, and must be capable of
being regenerated at temperatures similar to the reaction temperature, preferably using
only air. These stringent requirements required rapidly identifying a series of base
catalysts with high activity towards cracking, an additional series of potential additives
to mitigate coking and promote regeneration, and the final verification of their
combined properties to ensure optimal performance. Here we demonstrate a
comprehensive and iterative high-throughput (HT) methodology for identifying such
novel catalyst formulations with high activity towards cracking to LPG, which are
capable of being operated for extended periods of time and regenerated in air multiple
times without degradation in their activity. The approach combines a rapid, qualitative
primary optical screen via thin-film techniques, a series of quantitative screens using
mg powder quantities, and a final verification of the best samples using a single sample
reactor. This versatile approach permitted the systematic study of a large phase-space of
potential catalysts and additives combinations, ranging from noble metal promoted
simple oxide catalysts to zeolite based catalysts. Initial studies focused on the
identification of a catalyst with suitable activity, in excess of 20% conversion, using a
16-well reactor. This portion of the work focused on providing a comprehensive
quantification of the product distribution of the different catalysts using industrially
available catalyst formulations. Subsequently, thin-film samples with a spread of
compositions deposited as nanoparticles on the surface of the most active catalysts
were employed to screen bi-metallic additives for their relative coking and regeneration
rates. Several additives with the highest figure of merit were recommended for a second
round of screening of bi-metallic promoted zeolites in the 16-well reactor, where the
emphasis shifted to evaluating the effect of both the additives and multiple
regenerations on the product distribution. Final verification of the best additivemodified
catalyst was obtained in a single reactor in which the catalyst was run under a
highly concentrated feed for multiple days and demonstrated negligible degradation.
Keywords: High-throughput screening, catalysis, zeolite, oxide, impregnated,
ion-exchanged, ZSM-5, Pt, Gd, JP-8, LPG, catalytic cracking, thin film,
regeneration, fuel cracker.
