Biomass-based N doped carbon as metal-free catalyst for selective oxidation of D-xylose into D-xylonic acid

作者：Li, Zengyong; Huang, Yiming; Chi, Xiao; Li, Di; Zhong, Linxin; Li, Xuehui; Liu, Chuanfu^*; Peng, Xinwen^*

来源：Green Energy & Environment, 2022, 7(6): 1310-1317.

DOI：10.1016/j.gee.2021.01.004

• Biomass carbon
• Metal-free catalysts
• D-xylose
• Sugar acid
• Selective oxidation

Rational design and facile preparation of low-cost and efficient catalysts for the selective converting of biomass-derived monosaccharides into high value-added chemicals is highly demanded, yet challenging. Herein, we first demonstrate a N doped defect-rich carbon (NC-800-5) as metal-free catalyst for the selective oxidation of D-xylose into D-xylonic acid in alkaline aqueous solution at 100 degrees C for 30 min, with 57.4% yield. The doped graphitic N is found to be the active site and hydroxyl ion participating in the oxidation of D-xylose. Hydroxyl ion and D-xylose first adsorb on NC-800-5 surface, and the aldehyde group of D-xylose is catalyzed to form germinal diols ion. Then, C-H bond break to yield carboxylic group. Furthermore, NC-800-5 catalyst shows high stability in recycled test.