title: Engineering catalyst microenvironments for metal-catalyzed hydrogenation of biologically derived platform chemicals.
abstract: It is shown that microenvironments formed around catalytically active sites mitigate catalyst deactivation by biogenic impurities that are present during the production of biorenewable chemicals from biologically derived species. Palladium and ruthenium catalysts are inhibited by the presence of sulfur-containing amino acids; however, these supported metal catalysts are stabilized by overcoating with poly(vinyl alcohol) (PVA), which creates a microenvironment unfavorable for biogenic impurities. Moreover, deactivation of Pd catalysts by carbon deposition from the decomposition of highly reactive species is suppressed by the formation of bimetallic PdAu nanoparticles. Thus, a PVA-overcoated PdAu catalyst was an order of magnitude more stable than a simple Pd catalyst in the hydrogenation of triacetic acid lactone, which is the first step in the production of biobased sorbic acid. A PVA-overcoated Ru catalyst showed a similar improvement in stability during lactic acid hydrogenation to propylene glycol in the presence of methionine.
authors.affiliation: Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, WI 53706 (USA).
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Schwartz
authors.forename: Robert L
authors.initials: RL
authors.lastname: Johnson
authors.forename: Javier
authors.initials: J
authors.lastname: Cardenas
authors.forename: Adam
authors.initials: A
authors.lastname: Okerlund
authors.forename: Nancy A
authors.initials: NA
authors.lastname: Da Silva
authors.forename: Klaus
authors.initials: K
authors.lastname: Schmidt-Rohr
authors.forename: James A
authors.initials: JA
authors.lastname: Dumesic
mesh_terms: D000596:Amino Acids / Q000737:chemistry*; D002384:Catalysis; D020134:Catalytic Domain; D006865:Hydrogenation; D019216:Metals, Heavy / Q000037:antagonists & inhibitors / Q000737:chemistry*; D015394:Molecular Structure; D011142:Polyvinyl Alcohol / Q000737:chemistry*; D011753:Pyrones / Q000737:chemistry*
chemical_list: D000596:Amino Acids; D019216:Metals, Heavy; D011753:Pyrones; C030720:triacetic acid lactone; D011142:Polyvinyl Alcohol
keywords: biomass; biorenewable chemicals; catalyst stability; hydrogenation; nanocomposites