caa a22 4500 606173307 CHVBK 20210128100732.0 cr unu---uuuuu 210128e20151001xx s 000 0 eng 10.1007/s11244-015-0472-z doi (NATIONALLICENCE)springer-10.1007/s11244-015-0472-z Aerobic Oxidation of Veratryl Alcohol to Veratraldehyde with Heterogeneous Ruthenium Catalysts [Elektronische Daten] [M. Melián-Rodríguez, S. Saravanamurugan, S. Kegnæs, A. Riisager] Lignin is a complex polymeric molecule constituting various linkages between aromatic moieties. Typically, the β-O-4 linkage accounts for more than half of the linkage structures present in lignin. The current study focuses on the oxidative transformation of veratryl alcohol (VA)—a compound that can be formed by cleavage of β-O-4 linkages in lignin—to veratraldehyde (VAld) with air using ruthenium supported on γ-alumina or silica as catalyst with water or methanol as solvent in a batch reactor. Ru/Al2O3, prepared with ruthenium(IV)oxide hydrate showed superior catalytic activity, yielding 89% VAld in water at 160°C with 5bar air pressure after 8h of reaction. Prolonged reaction time led to significant formation of the decarbonylated product veratrol from VAld. When the reaction was completed under 20 bars of argon in methanol instead of water, the methyl ether of VA (i.e. 1,2-dimethoxy-4-(methoxymethyl)benzene) prevailed, indicating that methanol protected the hydroxyl group in VA from being oxidized to VAld. Catalysts containing alternative transition metals (Mn, Co, Cu and Ag) supported on Al2O3 gave significantly lower activities compared to Ru/Al2O3 under identical reaction conditions. The Ru/Al2O3 catalyst was reused in three consecutive reaction runs in water, but a decrease in VAld yield was obtained after the third cycle possibly due to leaching of Ru from the support. Springer Science+Business Media New York, 2015 Heterogeneous catalysis nationallicence Ruthenium nationallicence Oxidation nationallicence Veratryl alcohol nationallicence Veratraldehyde nationallicence Melián-Rodríguez M. Department of Chemistry, Centre for Catalysis and Sustainable Chemistry, Technical University of Denmark, Building 207, 2800, Kgs. Lyngby, Denmark aut Saravanamurugan S. Department of Chemistry, Centre for Catalysis and Sustainable Chemistry, Technical University of Denmark, Building 207, 2800, Kgs. Lyngby, Denmark aut Kegnæs S. Department of Chemistry, Centre for Catalysis and Sustainable Chemistry, Technical University of Denmark, Building 207, 2800, Kgs. Lyngby, Denmark aut Riisager A. Department of Chemistry, Centre for Catalysis and Sustainable Chemistry, Technical University of Denmark, Building 207, 2800, Kgs. Lyngby, Denmark aut Topics in Catalysis Springer US; http://www.springer-ny.com 58/14-17(2015-10-01), 1036-1042 1022-5528 58:14-17<1036 2015 58 11244 https://doi.org/10.1007/s11244-015-0472-z text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s11244-015-0472-z text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Melián-Rodríguez M. Department of Chemistry, Centre for Catalysis and Sustainable Chemistry, Technical University of Denmark, Building 207, 2800, Kgs. Lyngby, Denmark aut NATIONALLICENCE 700 1- Saravanamurugan S. Department of Chemistry, Centre for Catalysis and Sustainable Chemistry, Technical University of Denmark, Building 207, 2800, Kgs. Lyngby, Denmark aut NATIONALLICENCE 700 1- Kegnæs S. Department of Chemistry, Centre for Catalysis and Sustainable Chemistry, Technical University of Denmark, Building 207, 2800, Kgs. Lyngby, Denmark aut NATIONALLICENCE 700 1- Riisager A. Department of Chemistry, Centre for Catalysis and Sustainable Chemistry, Technical University of Denmark, Building 207, 2800, Kgs. Lyngby, Denmark aut NATIONALLICENCE 773 0- Topics in Catalysis Springer US; http://www.springer-ny.com 58/14-17(2015-10-01), 1036-1042 1022-5528 58:14-17<1036 2015 58 11244