ZTIF基疏水微介孔碳的制备及5-羟甲基糠醛吸附分离性能

Preparation of ZTIF based hydrophobic micro-mesoporous carbon and their adsorption and separation performance of 5-hydroxymethylfurfural

经过生物质酸性催化转化的5-羟甲基糠醛(5-HMF)原液的组成为低浓度水溶液、多组分酸性副产物乙酰丙酸(LA)和甲酸(FA),因此需要设计疏水、耐酸和高选择性的吸附剂来分离5-HMF。以高N的沸石型四氮唑-咪唑骨架材料(ZTIFs)为前体,通过调控碳化和活化条件制备具有耐酸性、疏水性和合适微介孔分布的多孔碳,利用多孔碳和5-HMF的π-π作用可实现含酸水溶液中5-HMF的高效富集分离。以ZTIF-8为前体,通过调控碳化温度和活化碱碳比,制备并筛选三种具有不同N含量和微介孔分布的ZTIF-8基多孔碳;建立ZTIF-8基多孔碳N含量和微介孔分布与5-HMF吸附分离性能的关系;具有低N含量和丰富大微孔小介孔(12~30Å,1Å=0.1 nm)的NC_(ZTIF-8)700C-800A2是从含酸性副产物水溶液中高效富集分离5-HMF的吸附剂。

The stock solution of 5-hydroxymethylfurfural(5-HMF)that has undergone acidic catalytic conversion of biomass is composed of a low-concentration aqueous solution and multi-component acidic by-products levulinic acid(LA)and formic acid(FA).Therefore,the design of 5-HMF separation adsorbents requires hydrophobicity,acid resistance,and high selectivity.In this work,porous carbon with acid resistance,hydrophobicity and suitable micro-mesoporous distribution were obtained by controlling carbonization temperature and activation conditions using high N-content zeolitic tetrazolate-imidazolate frameworks(ZTIFs)as precursors,and theπ-πinteraction between porous carbon and 5-HMF can be used to achieve efficient enrichment and separation of 5-HMF in acidcontaining aqueous solution.Three types of ZTIF-8 based porous carbon with different N-content and micromesoporous distribution were obtained by controlling carbonization temperature and activating alkali carbon ratio using ZTIF-8 as precursor.The relationship between the N-content and micro-mesoporous distribution of ZTIF-8 based porous carbon and the adsorption and separation performance of 5-HMF has been established.NC_(ZTIF-8)700C-800A2,with low N-content and abundant large micropores and small mesopores(12—30Å),is an adsorbent for efficient enrichment and separation of 5-HMF from aqueous solutions containing acidic by-products.