Location: Bio-oils ResearchTitle: Comparison of iridium-, ruthenium-, and osmium-catalyzed decarboxlyation catalysts of 9-cis-octadecenoic acid relevant to biobased fuel production
Submitted to: American Chemical Society National Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 6/18/2021
Publication Date: 7/14/2021
Citation: Doll, K.M., Moser, B.R. 2001. Comparison of iridium-, ruthenium-, and osmium-catalyzed decarboxlyation catalysts of 9-cis-octadecenoic acid relevant to biobased fuel production [abstract]. American Chemical Society National Meeting, August 22-26, 2021, Atlanta, GA. Abstract #3085081.
Technical Abstract: In prior research, conversion of biobased fatty acids into alkenes was reported utilizing triruthenium dodecacarbonyl. The resultant product is a family of isomerized linear alkenes. Observation was made of an interesting minor side reaction which forms aromatic alkenes. Later, this technology was extended to an osmium system, giving similar results. However, when an iridium system was utilized, the catalyst was found to be active, but gave a significantly different ratio of the aromatic to linear products. While the mechanism involving the isomerization of the double bonds of an unsaturated fatty acid, allowing rapid decarboxylation, was still observed, an alternative side reaction where hydrogenation/dehydrogenation occurs may account for the observed product differences. Utilizing this side reaction, these aromatic alkenes, an important component of biobased jet fuel, can be produced in increased content. A survey of iridium-containing catalysts was used in order to enhance the desired reaction while maintaining the reaction rate. Utilizing the best iridium catalyst, chloro-1,5-cyclooctadiene iridium (I) dimer, a yield of up to ~35% of the desired aromatic products was possible. Additionally, both the ruthenium and iridium systems were found to decarboxylate high-oleic soybean oil fatty acids, giving a product of similar energy content to that obtained using high grade oleic acid.