造纸污泥基固体酸催化D-果糖转化5-羟甲基糠醛

Papermaking sludge-derived Solid Acid as a Catalyst for D-Fructose Dehydration into 5-Hydroxymethylfurural

摘要:

以含有丰富金属离子的造纸污泥为原料，通过高温煅烧法制备生物炭（SBC），并与对氨基苯磺酸进行接枝，制备了一种高效碳基固体酸催化剂（S-SBC）。通过FTIR、XRD、SEM等对催化剂的组成、形貌、结构、酸负载量、比孔径及比表面积等进行表征。将该催化剂用于D-果糖转化为5-羟甲基糠醛（HMF）反应，对反应时间、反应温度、催化剂用量及溶剂种类、D-果糖质量分数等影响因素进行考察，并与用杨木为原料且采用相同方法制备的杨木炭催化剂（S-PBC）进行比较，结果表明，S-SBC的催化活性优于S-PBC。S-SBC同时含有由金属离子形成的Lewis酸位点以及—SO3H等形成的Brönsted酸位点，两种酸位点在催化D-果糖脱水制备5-羟甲基糠醛的过程中具有协同作用。S-SBC在二甲基亚砜中130 ℃下催化反应40 min， HMF收率高达95.2%。连续使用4次后，催化活性没有明显下降。

Abstract:

A high-efficiency carbon-based solid acid catalyst (S-SBC) is prepared by high-temperature calcination and p-aminobenzenesulfonic acid grafting using papermaking sludge with rich metal ions as raw materials. The composition, morphology, structure, acid load, specific pore size and specific surface area of the catalysts were investigated. The catalyst was used to catalyze the conversion of D-fructose to 5-hydroxymethylfurfural (HMF). The influence factors, such as reaction time, reaction temperature, catalyst mass fraction, solvent types and D-fructose concentration, were investigated and the poplar carbon catalyst (S-PBC) prepared by the same method was compared with S-SBC. The results show that the catalytic activity of S-SBC was better than that of S-PBC. S-SBC contains both Lewis acid sites formed by metal ions and Brönsted acid sites formed by -SO3H. The two acid sites have a synergistic effect in the process of catalyzing the dehydration of D-fructose to HMF. Using DMSO as the solvent, S-SBC catalyzed the reaction at 130 °C for 40 minutes, and the HMF yield was as high as 95.2%.After four consecutive uses, the catalytic activity did not decrease significantly.