Oxidative Esterification of 5‐Hydroxymethylfurfural with an N‐doped Carbon‐supported CoCu Bimetallic Catalyst

Abstract

The direct fabrication of furan‐2,5‐dimethylcarboxylate (FDMC), a promising renewable monomer, from biomass‐derived 5‐hydroxymethylfurfural (HMF) is a cutting‐edge process. In this contribution, an elaborately designed N‐doped carbon‐supported CoCu bimetallic catalyst (CoxCuy‐NC; x/y=9:1, 7:3, 4:6, which represents the designed molar ratio of Co and Cu in the catalyst), which could offer a desirable FDMC yield of 95 % under mild and base‐free conditions (Co7Cu3‐NC, 2 bar O2, 80 °C, 4 h) is described for the oxidative esterification of HMF. Notably, an FDMC formation rate of 6.1 molFDMC molCo−1 h−1 was achieved over Co7Cu3‐NC, which represents the highest catalytic efficiency so far among Co‐based catalytic systems. It has been demonstrated that Cu‐doping in Co7Cu3‐NC catalyst brings about more active sites (Co‐Nx species) with stronger molecular oxygen activation ability. The increase of surface N content of Co7Cu3‐NC also improves basicity of the catalyst, which favors the hydrogen abstraction process during the HMF oxidative esterification reaction. These findings may pave an efficient and green way for the synthesis of sustainable bio‐based polymer monomers.

Selective Oxidation of Furfural to 2(5H)-Furanone and Maleic Acid over CuMoO4

“…Since Cu(NO 3 ) 2 alone without PMS is inactive for furfural oxidation (Table S2, entry 11), the role of Cu(NO 3 ) 2 may be to enhance the oxidizing power by the redox cycle of NO 3 − /NO 2 /NO and Cu 2+ /Cu + , thus promoting the hydrogen abstraction of 2(5H)-furanone. 34,44 The above results confirmed that the increase in the oxidizing power was contributed to abstraction of the hydrogen of 2(5H)-furanone and the further oxidation to MAc. Additionally, the oxidation efficiency of furan to MAc increased slightly when air was replaced with O 2 , implying that there were a few improvements in the 5-position hydrogen abstraction of furfural by strengthening of oxidizing power.…”

Vitamin C-Assisted Synthesized Mn–Co Oxides with Improved Oxygen Vacancy Concentration: Boosting Lattice Oxygen Activity for the Air-Oxidation of 5-(Hydroxymethyl)furfural

“…The movement toward sustainable and greener replacements in the polymer industry has greatly promoted the development of biomass-derived renewable polymers to substitute petro-based commodity plastics. − Among engineering polyesters, poly­(ethylene terephthalate) (PET), a fossil-derived material, holds a tremendous global market of roughly 15 million metric tons, and global production of PET consumes approximately 0.2% of the global primary energy. , Therefore, it is of great significance and highly desirable to develop novel and renewable alternatives for PET. To this regard, polyethylene furandicarboxylate (PEF), a bioplastic fabricated by the polymerization of 2,5-furandicarboxylic acid (FDCA) and ethylene glycol (EG), has gained significant popularity as an intriguing 100% renewable-based replacement to PET. − More importantly, PEF has been hailed as the next-generation polymer because of its better gas impenetrability and physical properties than those of PET . While the economic production of EG from sustainable resources (such as carbohydrates) on a small industrial scale has already been accomplished, the production of FDCA on a pilot or commercial scale is still under development. − …”

Toward Value-Added Dicarboxylic Acids from Biomass Derivatives via Thermocatalytic Conversion

“…Few studies on FDMC synthesis from HMF were reported compared to FDCA. Heterogeneous catalysts, such as Au-based − and Co-based catalysts, − have been developed thus far. A Au/CeO 2 catalyst afforded a 99% yield and 6.3 mmol FDMC g cat –1 h –1 productivity of FDMC from HMF (1.3 wt %) at 130 °C and 1 MPa of O 2 in methanol .…”