Porous nitrogen-enriched carbonaceous material from marine waste: chitosan-derived carbon nitride catalyst for aerial oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid

Sanny Verma,Mallikarjuna N Nadagouda,Rajender S Varma

doi:10.1038/s41598-017-14016-5

Sanny Verma, Mallikarjuna N Nadagouda + Show 1 more

Open Access

https://doi.org/10.1038/s41598-017-14016-5

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Abstract

Chitosan-derived, porous nitrogen-enriched carbonaceous carbon nitride catalyst (PCNx) has been synthesized from marine waste and its use demonstrated in a metal-free heterogeneous selective oxidation of 5-hydroxymethyl-furfural (HMF) to 2,5-furandicarboxylic acid (FDCA) using aerial oxygen under mild reaction conditions.

Highlights

Growing demand for petroleum-derived products due to the waning reserves of fossil resources has prompted researchers to seriously consider the sustainable utilization of high-value chemicals and transportation fuels from readily available biomass resources1–6. 5-hydroxymethylfurfuryl (HMF) is one of the common but important platform chemical derived from carbohydrates and can be further upgraded to a variety of useful entities (Fig. 1) such as 2,5-furandicarboxylic acid (FDCA), 5-hydroxymethyl-2-furancarboxylic acid (HMFCA), 5-formyl-2-furancarboxylic acid (FFCA), maleic anhydride (MA) and 2,5-diformylfuran (DFF)7–11
Wu et al observed the efficient oxidation of HMF to FDCA with yields of 80% using metal-free N-doped nanoporous graphitic (NNC) catalyst at 80 °C under aerobic condition32; catalyst was synthesized via the pyrolysis of zeolitic imidazole frameworks such as ZIF-8 at 900 °C
Various carbon-based catalysts were examined namely graphite, graphene oxide (GO), carbon nanotubes (CNT), and carbon nanofibers (CNF) for the aerial oxidation of 5-HMF to FDCA using water as a solvent and K2CO3 as a base at different temperature (Table 1, entries 1–12); no FDCA production was discerned after 36 hours of reaction (Table 1, entries 1–12)

Summary

Synthesis and Characterization of Catalyst

The porous carbon nitride catalyst (PCNx) was synthesized via calcination of chitosan at 300 °C for 4 hours under nitrogen atmosphere. The ensuing PCNx catalyst was characterized using X-ray diffraction (XRD), transmission electron microscope (TEM), and Brunauer–Emmett–Teller (BET) analysis. The graphitic line (002) of the PCNx catalyst was observed at the diffraction peak of 24.97° corresponding to inter-layer spacing of about 0.345 nm which is usually attributed to a high degree of crystallinity of graphitic layers. This XRD pattern reveals a low content of amorphous carbon and impurities. TEM analysis shows porous structure of PCNx; wrinkles and bends are visible in Fig. 3 which are instigated by various defects. The porous nature of the material was further supported by BET surface area analysis and was found to be 92.83 m2/g

Results and Discussion

Conclusion

Additional Information