Catalytic hydrolysis of cellulose by phosphotungstic acid–supported functionalized metal-organic frameworks with different electronegative groups
- 43 Downloads
It is found that strong electronegative groups can selectively adsorb cellulose by hydrogen bonds. Grafting strong negatively charged groups onto catalysts to achieve the functionalization of the catalyst can give it the ability to selectively adsorb cellulose without affecting its catalysis, which is of great significance for the hydrolysis of cellulose. In this study, PTA@MIL-101–X (X = –Br, –NH2, –Cl, –NO2) materials were synthesized to investigate the effect of grafting different electronegative groups on carriers to the directional hydrolysis of cellulose. The synthesized catalysts used phosphotungstic acid as the catalytic center while treated MIL-101 structure as the carrier. The grafting of different electronegative groups changed the crystal structure of the metal organic framework without affecting its stability during the reaction. The strong negative functional groups can selectively adsorb cellulose by forming hydrogen bonds with cellulose hydroxyl groups and weaken the hydrogen bonds within cellulose molecules. This hydrogen bond can reduce the side reaction of glucose, lighten the difficulty of cellulose hydrolysis, and improve the efficiency of cellulose conversion at the same time. The hydrolysis rate of cellulose increased with the electronegativity enhancement of the grafted functional groups, and the grafted –NO2 catalyst PTA@MIL-101–NO2 obtained the highest glucose yield of 16.2% in the cellulose-directed hydrolysis. The –NH2 can form a chemical linkage with PTA through electrostatic interaction to get the highest immobilization stability and exhibit excellent stability in the recycling of catalysts.
KeywordsMetal-organic frameworks MIL-101 Immobilization Phosphotungstic acid Cellulose hydrolyzation
This work was supported by the National Natural Science Foundation of China (No. 31570568 and No. 31670585), the Science and Technology Planning Project of Guangzhou City, China (Nos. 201607010079 and 201607020007), the Science and Technology Planning Project of Guangdong Province, China (Nos. 2016A020221005 and 2017A040405022).
- Fazaeli R, Aliyan H, Masoudinia M, Heidari Z (2014) Building MOF bottles (MIL-101 family as heterogeneous single-site catalysts) around H3PW12O40 ships: an efficient catalyst for selective oxidation of sulfides to sulfoxides and sulfones. J Mater Chem EngGoogle Scholar
- Férey C, Mellot-Draznieks C, Serre C, et al (2005a) Chemistry: a chromium terephthalate-based solid with unusually large pore volumes and surface area. Science (80- ). https://doi.org/10.1126/science.1116275
- Férey G, Mellot-Draznieks C, Serre C, et al (2005b) A chromium terephthalate-based solid with unusually large pore volumes and surface area. Science (80- ). https://doi.org/10.1126/science.1116275
- Hu X, Lu Y, Dai F, Liu C, Liu Y (2013) Host-guest synthesis and encapsulation of phosphotungstic acid in MIL-101 via “bottle around ship”: an effective catalyst for oxidative desulfurization. Microporous Mesoporous Mater 170:36–44. https://doi.org/10.1016/j.micromeso.2012.11.021 CrossRefGoogle Scholar
- Khutia A, Rammelberg HU, Schmidt T et al (2013) Water sorption cycle measurements on functionalized MIL-101Cr for heat transformation application. https://doi.org/10.1021/cm304055k
- Lin Y, Kong C, Chen L (2012) Direct synthesis of amine-functionalized MIL-101(Cr) nanoparticles and application for CO<inf>2</inf> capture. RSC Adv 2. https://doi.org/10.1039/c2ra20641b
- Shrotri A, Kobayashi H, Fukuoka A (2016) Air oxidation of activated carbon to synthesize a biomimetic catalyst for hydrolysis of cellulose. 1299–1303. https://doi.org/10.1002/cssc.201600279
- Zhang C, Fu Z, Liu YC, et al (2012) Green chemistry ionic liquid-functionalized biochar sulfonic acid as a biomimetic catalyst for hydrolysis of cellulose and bamboo under microwave irradiation. 1928–1934. https://doi.org/10.1039/c2gc35071h