Chemically activated spruce organosolv lignin as a carbocatalyst for heterogeneous oxidative dehydrogenations in the liquid phase
|Author:||Lenarda, Anna1; Melchionna, Michele2; Aikonen, Santeri1;|
1Department of Chemistry, University of Helsinki, 00014 Helsinki, Finland
2Department of Chemical and Pharmaceutical Sciences, INSTM, University of Trieste, 34127 Trieste, Italy
3Research Unit of Sustainable Chemistry, University of Oulu, 90570 Oulu, Finland
4Department of Bioproducts and Biosystems, Aalto University, 02150 Espoo, Finland
|Online Access:||PDF Full Text (PDF, 6.5 MB)|
|Persistent link:|| http://urn.fi/urn:nbn:fi-fe20231108143541
American Chemical Society,
|Publish Date:|| 2023-11-08
Activated carbons obtained from organosolv lignin by chemical activation with KOH and oxidized with diluted HNO₃ were studied as catalysts for aerobic oxidative dehydrogenation (ODH) reactions. The structure/activity relationship was investigated through multiple techniques revealing the crucial role of oxygen functionality distribution in promoting two mechanistically archetypical ODH probe reactions: (i) the tetrahydroquinoline (THQ) aromatization, which represents ODH triggered by hydride transfer, and (ii) the 2-phenyl indole homocoupling reaction, a model for single-electron transfer-promoted reactions. In particular, the catalytic activity, correlating with oxygen functionality distribution on the basis of X-ray photoelectron spectroscopy and temperature-programmed desorption analysis, was associated with the C═O surface functionalities, as confirmed by blocking experiments with 2,2,2-trifluoroethyl hydrazine. Kinetic profiling tools were employed to assess THQ ODH product inhibition effects on the overall yield of the process as well as the extent of stoichiometric activity of the carbocatalyst. The breadth of the developed catalysts’ applicability was explored through selected relevant ODH reactions.
|Pages:||11362 - 11375|
|Type of Publication:||
A1 Journal article – refereed
|Field of Science:||
116 Chemical sciences
Financial support from the Academy of Finland [project no. 129062 (J.H.)] is acknowledged. The “Biocat” project funding from the Jane and Aatos Erkko Foundation is gratefully received (M.H. and J.H.).
© 2023 The Authors. Published by American Chemical Society. This publication is licensed under CC-BY 4.0.