A High-Performance Base-Metal Approach for the Oxidative Esterification of 5-Hydroxymethylfurfural

Exploring high‐performance base‐metal approaches for the sustainable production of chemicals from biomass is presently attracting immense interest and is truly important to promote their industrialized application. Herein, CoOx‐N/C and α‐MnO2 were combined as a base‐metal catalyst that can achieve high yields of furan‐2,5‐dimethylcarboxylate (FDMC, 95.6 %) for the catalytic oxidative esterification of 5‐hydroxymethylfurfural (HMF) without basic additive. The reaction proceeds through fast conversion of HMF to diformylfuran (DFF) with α‐MnO2 and subsequent transformation of DFF to FDMC by CoOx‐N/C. Quantitative X‐ray photoelectron spectroscopy (XPS) analysis and density functional theory (DFT) calculations indicated that the pyridinic‐N present in doped carbon could behave as a Lewis base to promote the ion of hydrogen for the oxidative esterification reaction. Consequently, CoOx‐N/C is a high performance catalyst for the synthesis of FDMC from DFF in a neutral medium. A high‐performance base‐metal approach for oxidative esterification of biomass‐derived platform 5‐hydroxymethylfurfural is presented. α‐MnO2/CoOx‐N/C achieved a 95.6 % yield of furan‐2,5‐dimethylcarboxylate in the absence of basic additives.