Base-free selective oxidation of monosaccharide into sugar acid by surface-functionalized carbon nanotube composites  

作　　者：Zengyong Li Di Li Linxin Zhong Xuehui Li Chuanfu Liu Xinwen Peng 

机构地区：[1]State Key Laboratory of Pulp and Paper Engineering,South China University of Technology,Guangzhou 510641,China [2]School of Chemistry and Chemical Engineering,South China University of Technology,Guangzhou 510641,China

出　　处：《Chinese Chemical Letters》2023年第11期116-123,共8页中国化学快报（英文版）

基　　金：supported by the National Youth Talent Support Program,National Natural Science Foundation of China(No.31971614);State Key Laboratory of Pulp and Paper Engineering(No.2022PY02);the National Program for Support of Topnotch Young Professionals(No.x2qsA4210090);Guangdong Basic and Applied Basic Research Foundation(Nos.2021A1515110205,2021A1515110622,2021A1515110245 and 2020A1515110705);Science and Technology Basic Resources Investigation Program of China(No.2019FY100900);the National Key Research and Development Program of China(No.2021YFC2101604).

摘　　要：Selective oxidation of biomass-derived monosaccharide into high value-added chemicals is highly desirable from sustainability perspectives.Herein,we demonstrate a surface-functionalized carbon nanotubesupported gold(Au/CNT-O and Au/CNT-N)catalyst for base-free oxidation of monosaccharide into sugar acid.Au/CNT-O and Au/CNT-N surfaces successfully introduced oxygen-and nitrogen-containing functional groups,respectively.The highest yields of gluconic acid and xylonic acid were 93.3%and 94.3%,respectively,using Au/CNT-N at 90℃ for 240 min,which is higher than that of using Au/CNT-O.The rate constants for monosaccharide decomposition and sugar acid formation in Au/CNT-N system were higher,while the corresponding activation energy was lower than in Au/CNT-O system.DFT calculation revealed that the mechanism of glucose oxidation to gluconic acid involves the adsorption and activation of O_(2),adsorption of glucose,dissociation of the formyl C-H bond and formation of O-H bond,and formation and desorption of gluconic acid.The activation energy barrier for the glucose oxidation over Au/CNT-N is lower than that of Au/CNT-O.The nitrogen-containing functional groups are more beneficial for accelerating monosaccharide oxidation and enhancing sugar acid selectivity than oxygen-containing functional groups.This work presents a useful guidance for designing and developing highly active catalysts for producing high-value-added chemicals from biomass.

关 键 词：Surface functionalization Base-free oxidation Sugar acid Kinetic study DFT calculation 

分 类 号：O64[理学—物理化学]