(538b) Deactivation of Ptsn/C Catalysts for the Decarboxylation of Butyric Acid in High Temperature Water

Lipid-rich biomass sources, such as algae, have attracted attention for the production of renewable fuels.  Hydrothermal processing of algae produces free fatty acids from hydrolysis of triglycerides, phospholipids, and other lipids.  Pt has been shown to be an effective decarboxylation catalyst for saturated fatty acids in hydrothermal environments.  Decarboxylation produces alkanes and alkenes and thus provides a path to fully hydrocarbon fuels from renewable feedstocks.  Though the efficacy of Pt is known, the long-term stability and activity maintenance of Pt catalysts under hydrothermal conditions is not known.  Thus, we embarked on an investigation of catalyst deactivation during hydrothermal treatment of carboxylic acids.  We designed, built, and operated a packed bed flow reactor to determine the activity of different catalysts for up to a few days of time on stream,  PtSn alloys have been shown to resist deactivation better than Pt alone and increase the selectivity of certain reactions such as dehydrogenation of hydrocarbons.  Thus, PtSn/C catalysts with Sn loadings ranging from 0 to 20 mol% with respect to Pt were used to perform the decarboxylation of butyric acid, a model compound for free fatty acids from algae.  The reactions were performed at 350 ˚C for up to 48 hours of continuous use.  The focus of this talk will be on the effect of Sn loading on the selectivity and degradation of Pt based catalysts for the decarboxylation of butyric acid.