木质纤维生物质的电化学催化研究进展

Electrocatalytic oxidation and reduction of biomass-derived chemicals:a review

电催化是一种可以将电能转化为化学能的清洁、高效转化技术。在生物质精炼的各种策略中,电催化主要通过电子从电极表面转移到反应底物,在阳极和阴极分别发生氧化和还原反应,将生物质衍生物转化为高附加值的产品。总结了几种代表性的木质纤维生物质衍生物,如糠醛、5-羟甲基糠醛(HMF)、木质素及其衍生物等,通过电催化反应转化为高附加值化学品的最新进展。其中,在生物质衍生物的电还原反应中,糠醛的电还原产物主要是糠醇和2-甲基呋喃,HMF的电还原产物主要包括2,5二甲基呋喃和2,5-二羟甲基四氢呋喃等;酚类化合物通过加氢脱氧可还原为高碳氧比、稳定的芳香烃类化学品;在生物质衍生物的电氧化反应中,糠酸是糠醛主要的电氧化产物,HMF主要的电氧化产物是为2,5-呋喃二羧酸;木质素可以通过电催化氧化转化为香兰素、愈创木酚等。讨论了电催化过程中的催化剂和反应参数(如电极电位、pH等)对生物质衍生物电催化效率的影响以及相应的反应机理,并对电催化应用于生物质高值化利用领域的发展趋势进行了展望。

Electrocatalysis is a clean and efficient conversion technology that can convert electrical energy into chemical energy and provide an approach to store large scale renewable energy(wind,solar)in chemical bonds.In recent years,a significant advancement has been achieved in the application of electrocatalysis in the sustainable conversion of biomass derived molecules.Electrocatalysis mainly transfers electrons from the electrode surface to the reaction substrates.The oxidation and reduction reactions take place at the anode and cathode respectively to convert biomass derivatives into high value-added products.The reaction conditions are mild,and the products are easy to control.Also,hydrogen source and oxygen sources are mainly supplied by the ionization of H_(2)O to avoid the use of H_(2) or oxidizer sources.In this review,the latest development of several representative lignocellulosic biomass derivatives,such as furfural,5-hydroxymethylfurfural(HMF),lignin and lignin derivatives(phenolic compounds),are discussed.Among them,the electroreduction products of furfural are mainly furfuryl alcohol and 2-methylfuran,which are the intermediates of synthetic polymer(furan resin)and pharmaceutical,respectively.The electroreduction products of HMF mainly include 2,5-dimethylfuran(DMF)and 2,5-dihydroxymethyl tetrahydrofuran(DHMTHF),which are high-performance liquid fuels and special solvents respectively.Phenolics can be reduced to stable aromatic hydrocarbons with high C/O ratio by hydrodeoxygenation.As a main electro oxidation product of furfural,furoic acid is a raw material for the synthesis of methyl furan,furfuramide and furfuryl ester in the process of electro oxidation of biomass derivatives.As the main electro oxidation product of HMF,2,5-furan dicarboxylic acid(FDCA)is a renewable monomer for polycondensation.Lignin can be converted into vanillin and guaiacol by electrocatalytic oxidation,which can be used as intermediates in the synthesis of medicine,perfume and other products.The effects of electrode materials and reaction parameters(such as electrode potential,pH value,etc.)on the electrochemical catalytic efficiency of biomass and the corresponding reaction mechanism are discussed.Finally,the perspective on development trend of electrocatalysis in the field of high value utilization of biomass is proposed.