Selectively Upgrading Lignin Derivatives to Carboxylates through Electrochemical Oxidative C(OH)-C Bond Cleavage by a Mn-Doped Cobalt Oxyhydroxide Catalyst

Hua Zhou; Zhenhua Li; Si-Min Xu; Lilin Lu; Ming Xu; Kaiyue Ji; Ruixiang Ge; Yifan Yan; Lina Ma; Xianggui Kong; Lirong Zheng; Haohong Duan

doi:10.1002/anie.202015431

Selectively Upgrading Lignin Derivatives to Carboxylates through Electrochemical Oxidative C(OH)-C Bond Cleavage by a Mn-Doped Cobalt Oxyhydroxide Catalyst

Angew Chem Int Ed Engl. 2021 Apr 12;60(16):8976-8982. doi: 10.1002/anie.202015431. Epub 2021 Mar 10.

Authors

Hua Zhou¹, Zhenhua Li², Si-Min Xu², Lilin Lu³, Ming Xu², Kaiyue Ji¹, Ruixiang Ge¹, Yifan Yan², Lina Ma², Xianggui Kong², Lirong Zheng⁴, Haohong Duan¹

Affiliations

¹ Department of Chemistry, Tsinghua University, Beijing, 100084, China.
² State Key Laboratory of Chemical Resource Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing, 100029, China.
³ School of Chemistry and Chemical Engineering, Wuhan University of Science and Technology, Wuhan, 430081, China.
⁴ Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China.

PMID: 33555646
DOI: 10.1002/anie.202015431

Abstract

Oxidative cleavage of C(OH)-C bonds to afford carboxylates is of significant importance for the petrochemical industry and biomass valorization. Here we report an efficient electrochemical strategy for the selective upgrading of lignin derivatives to carboxylates by a manganese-doped cobalt oxyhydroxide (MnCoOOH) catalyst. A wide range of lignin-derived substrates with C(OH)-C or C(O)-C units undergo efficient cleavage to corresponding carboxylates in excellent yields (80-99 %) and operational stability (200 h). Detailed investigations reveal a tandem oxidation mechanism that base from the electrolyte converts secondary alcohols and their derived ketones to reactive nucleophiles, which are oxidized by electrophilic oxygen species on MnCoOOH from water. As proof of concept, this approach was applied to upgrade lignin derivatives with C(OH)-C or C(O)-C motifs, achieving convergent transformation of lignin-derived mixtures to benzoate and KA oil to adipate with 91.5 % and 64.2 % yields, respectively.

Keywords: C−C bond cleavage; carboxylic acids; electrochemical oxidation; hydrogen evolution; lignin upgrading.

Abstract

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