电化学催化氧阴极还原协同阳极氧化一步完成纤维木质素选择性溶出及深度氧化的机理研究

The electrocatalyzed catihodic oxygen reduction-anodic oxidation reaction system was successfully applied to pulp bleaching based on the produced hydroxyl radical and hydrogen peroxide during the electochemical process by applicant's research group to fullfill the delignification of fibers as well as the advanced oxidation of dissolved lignin fragment in one pot style,which will boost the pulp bleaching industry significantly. However, the mechanism of this electrocatalyzed delignification of pulp fibers was not clear so far. This proposal will pay more attention on the mechanism, in which lignin models, cellulose model, lignin and pulp fibers are going to be used to investigate the reaction route and final oxidized products. ESR, FTIR, NMR, LC-MS as well as CP-GC-MS are involved to analyze the structure changes for lignin and lignin fragments as well as cellulosic fiber. The reaction dynamics and reaction routes for the delignification of pulp fibers as well as the extended oxidization of lignin fragments will be obtained and clarify the related reaction mechanism which not only can offer the foundation of electrocatalyzed cathodic oxygen reduction-anodic oxidation pulp delignification, but also can guide the application of this pulp bleaching method in the industry.

该项目将电化学催化氧阴极还原协同阳极氧化体系用于纸浆漂白，项目组通过工艺调控实现了单一体系中一步完成纤维中木质素的选择性溶出与溶出木素的深度氧化。然而，该电化学体系中纤维木质素的选择性溶出与溶出木质素的深度氧化同步进行机理仍不清晰。该项目从电化学阴阳两极协同催化体系中HO•和H2O2的产生规律以及调控因素入手，以木素模型物、纤维素模型物、木质素以及木材纤维为研究对象，通过对各目标物的电化学催化反应动力学以及利用NMR、LCMS、CP-GC-MS等手段对各目标物的反应产物及特性进行分析，弄清该电化学体系中纤维木质素的降解溶出调控机制，明确溶出木素及纸浆中木素的降解产物和反应途径，得到木质素及纤维素性能及结构变化规律，最终获得电催化氧阴极还原协同阳极氧化用于纸浆漂白时木质素的选择性溶出与深度降解一步完成机理，为进一步寻求高效清洁纸浆电化学漂白提供理论基础，为其工业化应用提供技术支持。

该项目针对电化学催化氧阴极还原协同阳极氧化体系用于纸浆漂白时一步完成纤维中木质素的溶出以及溶出木素的深度氧化过程，以木素模型物、纤维素模型物、木质素以及木材纤维为研究对象，利用电子自旋共振仪从HO•和H2O2的产生规律以及调控因素入手，通过对各目标物的电化学催化反应动力学以及利用FTIR、NMR、LCMS、CP-GC-MS等手段对各目标物的反应产物及特性进行了分析和研究，清晰了该电化学体系中纤维木质素的降解溶出调控机制和规律，明确了溶出木素及纸浆中木素的降解产物和反应途径，得到了木质素及纤维素性能及结构变化规律，最终对于电催化氧阴极还原协同阳极氧化用于纸浆漂白时木质素的溶出及深度降解一步完成机理有了深入了解，为进一步寻求高效清洁纸浆电化学漂白提供了理论基础，为其工业化应用提供了技术支持。