不同碳源制备碳基固体酸及其在水解纤维素中的应用

采用磁性碳纳米管(CNTs)、葡萄糖、炼焦酚渣为碳源,制得碳基固体酸催化剂.通过XRD、FTIR、13C NMR和SEM/TEM对其结构和活性基团进行表征,并且以经过预处理的微晶纤维素为纤维素模型物,以总还原糖得率为考察指标,利用制备的碳基固体酸非均相催化水解纤维素,比较了3种碳源制得的碳基固体酸在水解纤维素中的水解效率.研究结果表明,与传统原料葡萄糖制得的碳基固体酸相比,酚渣基固体酸碳环上除了含有酚羟基、羧基和磺酸基外,还含有其它碳基固体酸不具备的烷基侧链,这一结构优势对碳基固体酸催化剂的催化活性具有促进作用,能够提高碳基固体酸催化剂的水解效率；碳纳米管固体酸尽管具有致密的碳层结构、磺化后磺酸密度低,但高比表面积使其在非均相催化水解纤维素中表现出较高的活性.

Synthesis and properties in hydrolytic cellulose of carbon-based solid acids prepared from different carbon sources

Three kinds of carbon-based solid acid were prepared from carbon nanotubes(CNTs),glucose and phenolic residue,respectively.The structural information of these solid acids was investigated by XRD,FT-IR,13C NMR and SEM/TEM.The carbon-based solid acids were used to hydrolyze pretreatment microcrystal cellulose as catalyst,in which the yield of reducing sugar was used to evaluate the hydrolysis efficiency of catalysts.The results indicate that compared with the traditional carbon-based solid acid from glucose,the phenolic residual-based solid acid also contains aliphatic side chains except phenolic—OH,COOH and SO3H.This structure is beneficial to catalytic activity of carbon-based solid acid and improves its hydrolytic efficiency.Although CNTs has the pyknotic carbon structure and low density of SO3H,its high specific area shows high hydrolytic efficiency in heterogeneous catalytic reaction of hydrolytic cellulose.