M-Gallate (M = Ni, Co) Metal–Organic Framework-Derived Ni/C and Bimetallic Ni–Co/C Catalysts for Lignin Conversion into Monophenols

作者：Jin Zhu, Fuqiang Chen, Zhiguo Zhang, Min Li, Qiwei Yang, Yiwen Yang, Zongbi Bao, Qilong Ren · 发表于：ACS Sustainable Chemistry & Engineering · 年份：2019 · DOI：10.1021/acssuschemeng.9b02005 · 被引用次数：107 · 研究领域：Lignin and Wood Chemistry、Catalysis and Hydrodesulfurization Studies、Catalysis for Biomass Conversion

Lignin is the only renewable source of aromatic compounds in nature, and high value-added monophenolic compounds can be obtained by depolymerizing lignin. This work reported a facile strategy for preparation of monometallic and bimetallic nonprecious catalysts for hydrogenolysis of lignin. Both Ni/C and bimetallic Ni–Co/C catalysts are synthesized starting from gallate-based MOFs, namely, M-gallate (M = Ni, Co), as a self-sacrificing precursor for calcination treatment. Gallic acid was used as the supporter of metal and a carbon source for carbothermal reduction of metal oxide to form well-dispersed metal nanoparticles during the calcination process. The prepared catalyst was characterized by PXRD, XPS, and STEM. The bimetallic catalyst Ni x Co 1– x /C could form an alloy structure to produce a synergistic catalytic effect and greatly improve catalytic activity of lignin depolymerization. The highest yield of monophenols with Ni 0.5 Co 0.5 /C catalysts can reach 55.2%, and the guaiacol selectivity was as high as 70.3%. The depolymerization reaction of the lignin model compound guaiacylglycerol-β-guaiacyl ether (GG) revealed that the β-O-4 bond will be selectively broken, and the benzene ring will not overhydrogenated with Ni/C and the Ni 0.5 Co 0.5 /C catalyst.