Dehydration of Carbohydrates to 5‑Hydroxymethylfurfural over Lignosulfonate-Based Acidic Resin

Lignosulfonate-based renewable solid acids were first utilized as effective catalysts for fructose dehydration to produce 5-hydroxymethylfurfural (HMF). Among the investigated catalysts, the LF resin synthesized with formaldehyde and sodium lignosulfonate demonstrated the highest activity and good stability. Over it, similar to 90% HMF carbon yield was reached at 393 K. On the basis of the characterization results of N-2-physisorption, chemical titration, and microcalorimetric measurement of NH3 adsorption, the outstanding performance of LF resin should be interpreted by its higher acid strength and/or the synergistic effect of adjacent -SO3H, -COOH and phenolic -OH surface functional groups. We also explored the applicability of the LF resin for HMF production using other cheaper carbohydrates. Here, 73% HMF carbon yield was obtained from inulin hydrolysis/dehydration after the reaction was conducted over the LF resin at 393 K for 2.5 h.

基于木质素磺酸盐的可再生固体酸首次被用作果糖脱水生产5 - 羟甲基糠醛（HMF）的有效催化剂。在所研究的催化剂中，由甲醛和木质素磺酸钠合成的LF树脂表现出最高的活性和良好的稳定性。在其作用下，在393 K时，HMF的碳收率达到约90%。根据N₂物理吸附、化学滴定以及氨吸附微量热测量的表征结果，LF树脂的优异性能应归因于其较高的酸强度和/或相邻的 - SO₃H、 - COOH和酚羟基表面官能团的协同作用。我们还探索了LF树脂用于使用其他更廉价的碳水化合物生产HMF的适用性。在此，在393 K下使用LF树脂反应2.5小时后，从菊粉水解/脱水过程中获得了73%的HMF碳收率。