Selective Hydrogenolysis of Lignin Model Compounds to Aromatics over a Cobalt Nanoparticle Catalyst

Abstract

Catalytic conversion of renewable lignin to aromatics can effectively alleviate the fossil resource crisis. Herein, we prepared porous nitrogen-doped carbon-supported cobalt nanoparticle catalyst (CoNC) using a SiO2 template and tested its catalytic performance for cleavage of the β-O-4 ether bond in lignin model compounds. It was found that the catalyst pyrolyzed in a nitrogen atmosphere at 900 °C (CoNC-900) could catalyze 2-phenoxyacetophenone to ethylbenzene and phenol effectively, affording both in 99.0% yields. Further study indicated that the catalytic system was efficient for transformation of various β-O-4 ketones with methoxyl groups with high yields of desired products. The excellent catalytic performance was related to the cobalt nanoparticles, large pore volume, and specific surface area. Furthermore, the catalyst could be reused five times without obvious loss of the activity, indicating its stability during the reaction process. The reaction pathway was studied on the basis of some control experiments.

Facile preparation of N-doped graphitic carbon encapsulated nickel catalysts for transfer hydrogenolysis of lignin β-O-4 model compounds to aromatics

“…In addition, when the reaction time is longer than 4 h, the conversion and the yields of phenol and ethylbenzene remained nearly constant as shown in Fig. 4(a 45 . Thus, in this work, transfer hydrogenolysis of a lignin b-O-4 ketone model compound, 2-phenoxyacetophenone, was further explored over Ni@NC-800, Ni@NC-800-H and Ni/NC-800.…”

“…Recently, a two-step strategy has been proposed in the transformation of lignin β-O-4 model compounds: the oxidation of C α –OH of β-O-4 alcohol to β-O-4 ketone, which can lower the C β –O bond dissociative energy (BDE) by 40–50 kJ mol −1 , followed by the hydrogenolysis of the C β –O bond 45 . Thus, in this work, transfer hydrogenolysis of a lignin β-O-4 ketone model compound, 2-phenoxyacetophenone, was further explored over Ni@NC-800, Ni@NC-800-H and Ni/NC-800.…”

“…7 Thus, selective cleavage of the b-O-4 linkages is of great importance for lignin depolymerization. [8][9][10] Hydrogenolysis is regarded as an effective way to obtain aromatic chemicals from lignin. 11,12 Noble metal catalysts (Pt, Pd, Rh and Ru) exhibit excellent catalytic activity for the hydrogenolysis of lignin and its model compounds under mild conditions.…”

Fabricating Bifunctional Co−Al2O3@USY Catalyst via In‐Situ Growth Method for Mild Hydrodeoxygenation of Lignin to Naphthenes

“…They found that the addition of Ru could improve the hydrogenolysis reactivity. Wu et al [16] reported that 2-phenoxyacetophenone could be converted to ethylbenzene and phenol with 99.0 % yields over CoNC catalyst at 220 °C. Mauriello et al [13b] reported that Pd/Co catalyst could convert benzyl phenyl ether to toluene and cyclohexanol with 50 % yields at 240 °C.…”

“…They found that the addition of Ru could improve the hydrogenolysis reactivity. Wu et al [16] . reported that 2‐phenoxyacetophenone could be converted to ethylbenzene and phenol with 99.0 % yields over CoNC catalyst at 220 °C.…”