TY  - JOUR
AU  - Zhang, Chaofeng
AU  - Li, Hongji
AU  - Lu, Jianmin
AU  - Zhang, Xiaochen
AU  - MacArthur, Katherine
AU  - Heggen, Marc
AU  - Wang, Feng
TI  - Promoting Lignin Depolymerization and Restraining the Condensation via an Oxidation-Hydrogenation Strategy
JO  - ACS catalysis
VL  - 7
IS  - 5
SN  - 2155-5435
CY  - Washington, DC
PB  - ACS
M1  - FZJ-2017-06687
SP  - 3419 - 3429
PY  - 2017
AB  - For lignin valorization, simultaneously achieving the efficient cleavage of ether bonds and restraining the condensation of the formed fragments represents a challenge thus far. Herein, we report a two-step oxidation–hydrogenation strategy to achieve this goal. In the oxidation step, the O2/NaNO2/DDQ/NHPI system selectively oxidizes CαH–OH to Cα═O within the β-O-4 structure. In the subsequent hydrogenation step, the α-O-4 and the preoxidized β-O-4 structures are further hydrogenated over a NiMo sulfide catalyst, leading to the cleavage of Cβ–OPh and Cα–OPh bonds. Besides the transformation of lignin model compounds, the yield of phenolic monomers from birch wood is up to 32% by using this two-step strategy. The preoxidation of CαH–OH to Cα═O not only weakens the Cβ–OPh ether bond but also avoids the condensation reactions caused by the presence of Cα+ from dehydroxylation of CαH–OH. Furthermore, the NiMo sulfide prefers to catalyze the hydrogenative cleavage of the Cβ–OPh bond connecting with a Cα═O rather than catalyze the hydrogenation of Cα═O back to the original CαH–OH, which further ensures and utilizes the advantages of preoxidation.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000401054300041
DO  - DOI:10.1021/acscatal.7b00148
UR  - https://juser.fz-juelich.de/record/837917
ER  -