Karnitski, Aliaksandr Choi, Jae-Wook Suh, Dong Jin Yoo, Chun-Jae Lee, Hyunjoo Kim, Kwang Ho Kim, Chang Soo Kim, Kyeongsu Ha, Jeong-Myeong 2024-01-19T10:01:27Z 2024-01-19T10:01:27Z 2023-04-13 2023-03 0920-5861 https://pubs.kist.re.kr/handle/201004/113921 Lignin is a natural polymer contained in lignocellulose and is a potential feedstock for the production of phe-nolics or small aromatic molecules. However, lignin depolymerization is typically performed using low lignin concentrations and insufficiently active catalysts, which hinders industrial applications. To address this issue, we herein investigated the depolymerization of concentrated kraft lignin and oak-extracted organosolv lignin pro-moted by supported bifunctional metal (palladium)-acid catalysts and elucidated the roles of acid and metal sites. In addition to acid sites, which are known to be critical for lignin degradation, metal sites were found to be required to initiate lignin depolymerization. Palladium atoms promoted depolymerization even in the absence of acid sites, while acid site-promoted depolymerization required the presence of surface palladium atoms. Cata-lysts with bulk palladium particles were much more active than those with highly dispersed palladium particles, which suggested that efficient depolymerization required the bulky lignin polymer to be adsorbed on the palladium surface in a multidentate fashion. Thus, our work provides valuable insights into the mechanism of catalytic lignin depolymerization and paves the way to the industrial-scale application of this process. English Elsevier BV Roles of metal and acid sites in the reductive depolymerization of concentrated lignin over supported Pd catalysts Article 10.1016/j.cattod.2022.07.012 1 Catalysis Today, v.411 Catalysis Today 411 Y scie scopus 000956118400001 2-s2.0-85135083501 Chemistry, Applied Chemistry, Physical Engineering, Chemical Chemistry Engineering Article SUPERCRITICAL ETHANOL PHENOLIC HYDROCARBONS ORGANOSOLV LIGNIN ALKALI LIGNIN CONVERSION HYDROGENOLYSIS EFFICIENT SOFTWOOD Kraft lignin Organosolv lignin Depolymerization Palladium Acid Metal dispersion