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The aerobic oxidation of 5‐hydroxymethylfurfural (HMF) to 2,5‐furandicarboxylic acid (FDCA), a promising renewable monomer to produce bio‐based polymers such as polyethylene furanoate (PEF), has recently emerged as the subject of increasing interest. Here, holey 2 D Mn2O3 nanoflakes were obtained by a facile thermal treatment of a Mn‐based metal–organic framework (MOF) precursor. The structural and morphological properties of the nanoflakes were characterized by powder XRD, FTIR, SEM and TEM to explore the formation process. It was inferred that the linker loss in the MOF precursor and the oxidation of the Mn cation induced by the heat‐treatment in air were responsible for the formation of holey 2 D Mn2O3 nanoflakes. The specific morphology and redox cycle of the Mn cation on the surface endowed the synthesized nanoflakes with promising performance on the selective oxidation. The obtained nanoflakes calcined at 400 °C (M400) afforded over 99.5 % yield of FDCA at complete conversion of HMF, which is superior to the catalytic activity of commercial Mn2O3 and activated MnO2. To our knowledge, Mn2O3 exhibiting such a high performance on the aerobic oxidation of HMF to FDCA has not yet been reported. Based on the investigation of the experimental parameters, a plausible reaction mechanism was proposed. [ABSTRACT FROM AUTHOR]

The separation of ethylene (C 2 H 4 ) from C 2 hydrocarbons is considered as one of the most difficult and important processes in the petrochemical industry. Heat-driven cryogenic distillation is still widely used in the C 2 hydrocarbons separation realms, which is an energy intensive process and takes up immense space. In response to a greener, more energy-efficient sustainable development, we successfully synthesized a multifunction microporous Mg-based MOF [Mg 2 (TCPE)(μ 2 -OH 2 )(DMA) 2 ]·solvents ( NUM-9 ) with C 2 H 6 /C 2 H 2 selectivity based on a physical adsorption mechanism, and with outstanding stability; especially, it is stable up to 500 °C under an air atmosphere. NUM-9a (activated NUM-9 ) shows good performances in the separation of C 2 H 6 /C 2 H 2 from raw ethylene gases. In addition, its actual separation potential is also examined by IAST and dynamic column breakthrough experiments. GCMC calculation results indicate that the unique structure of NUM-9a is primarily conducive to the selective adsorption of C 2 H 6 and C 2 H 2 . More importantly, compared with C 2 H 4 , NUM-9a prefers to selectively adsorb C 2 H 6 and C 2 H 2 simultaneously, which makes NUM-9a as a sorbent have the capacity to separate C 2 H 4 from C 2 hydrocarbon mixtures under mild conditions through a greener and energy-efficient separation strategy.

The aerobic oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA), a promising renewable monomer to produce bio-based polymers such as polyethylene furanoate (PEF), has recently emerged as the subject of increasing interest. Here, holey 2 D Mn 2 O 3 nanoflakes were obtained by a facile thermal treatment of a Mn-based metal-organic framework (MOF) precursor. The structural and morphological properties of the nanoflakes were characterized by powder XRD, FTIR, SEM and TEM to explore the formation process. It was inferred that the linker loss in the MOF precursor and the oxidation of the Mn cation induced by the heat-treatment in air were responsible for the formation of holey 2 D Mn 2 O 3 nanoflakes. The specific morphology and redox cycle of the Mn cation on the surface endowed the synthesized nanoflakes with promising performance on the selective oxidation. The obtained nanoflakes calcined at 400 °C (M400) afforded over 99.5 % yield of FDCA at complete conversion of HMF, which is superior to the catalytic activity of commercial Mn 2 O 3 and activated MnO 2 . To our knowledge, Mn 2 O 3 exhibiting such a high performance on the aerobic oxidation of HMF to FDCA has not yet been reported. Based on the investigation of the experimental parameters, a plausible reaction mechanism was proposed., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

As a new type of porous material, metal-organic frameworks (MOFs) have been widely studied in gas adsorption and separation, especially in C 2 hydrocarbons. Considering the stronger interaction between the unsaturated molecules and the metal sites, and the smaller molecular size of unsaturated molecules, the usual relationship of affinities and adsorption capacities among C 2 hydrocarbons in most common MOFs is C 2 H 2 > C 2 H 4 > C 2 H 6 . Herein, a unique microporous metal-organic framework, NUM-7a (activated NUM-7 ), with a completely reversed adsorption relationship for C 2 hydrocarbons (C 2 H 6 > C 2 H 4 > C 2 H 2 ) has been successfully synthesized, which breaks the traditional concept of the adsorption relationship of MOFs for C 2 hydrocarbons. Based on this unique adsorption relationship, a green and simple one-step separation purification for a large amount of C 2 H 4 can be expected to be achieved through the selective adsorption of C 2 H 6 . In addition, NUM-7a also shows good selectivities in C 2 H 2 /CO 2 and CO 2 /CH 4 .