Investigating (Pseudo)-Heterogeneous Pd-Catalysts for Kraft Lignin Depolymerization under Mild Aqueous Basic Conditions

Catalysts

Cyril Aymonier¹  Yu Xu¹  Guillaume Aubert¹  Pascal Fongarland²  Régis Philippe²  Laurent Djakovitch³  Laurence Burel³  Dolorès Bourbiaux³  Firat Goc³  Franck Rataboul³ 

[1] CNRS, Bordeaux INP, ICMCB, Université de Bordeaux, UMR 5026, 87 Avenue du Docteur Schweitzer, CEDEX, 33600 Pessac, France;CNRS, CPE-Lyon, CP2M, Université de Lyon, Université Claude Bernard Lyon 1, UMR 5128, 43 Boulevard du 11 Novembre 1918, CEDEX, 69616 Villeurbanne, France;CNRS, IRCELYON, Université de Lyon, Université Claude Bernard Lyon 1, UMR 5256, 2 Avenue Albert Einstein, CEDEX, 69626 Villeurbanne, France;

关键词: lignin;    oxidative depolymerization;    heterogeneous catalysis;    metallic nanoparticles;    palladium;   

DOI  :  10.3390/catal11111311

来源: DOAJ

【 摘 要 】

Lignin is one of the main components of lignocellulosic biomass and corresponds to the first renewable source of aromatic compounds. It is obtained as a by-product in 100 million tons per year, mainly from the paper industry, from which only 2–3% is upgraded for chemistry purposes, with the rest being used as an energy source. The richness of the functional groups in lignin makes it an attractive precursor for a wide variety of aromatic compounds. With this aim, we investigated the Pd-catalyzed depolymerization of lignin under mild oxidizing conditions (air, 150 °C, and aqueous NaOH) producing oxygenated aromatic compounds, such as vanillin, vanillic acid, and acetovanillone. Palladium catalysts were implemented following different strategies, involving nanoparticles stabilized in water, and nanoparticles were supported on TiO₂. Significant conversion of lignin was observed in all cases; however, depending on the catalyst nature and the synthetic methods, differences were observed in terms of selectivity in aromatic monomers, mainly vanillin. All these aspects are discussed in detail in this report, which also provides new insights into the role that Pd-catalysts can play for the lignin depolymerization mechanism.

【 授权许可】

Unknown