催化剂金属及载体促进木质素加氢研究进展

Advances in catalyst metals and supports for lignin hydrogenation

发展木质素资源化利用技术以获得高附加值芳香族化学品,不仅能提高木质素的经济价值,还有助于实现“双碳”目标。近年来,大量研究集中在木质素的加氢解聚。根据氢供体的不同,木质素的加氢解聚可以分为外源氢供氢(包括氢气、醇溶剂或甲酸)和内源氢供氢(木质素自转移氢解)。木质素的加氢解聚具有高产率、组成简单等优势。然而,苛刻的反应条件促使人们开发高效的加氢催化剂。提升加氢催化剂性能的研究重点在于金属活性位点和载体活性位点的调控。通过对大量木质素加氢催化剂的研究,梳理了木质素加氢解聚的研究进展,分析了催化剂金属活性位点的亲氧性和尺寸效应对木质素外源氢供氢解聚的产物分布和自转移氢解的影响规律,归纳了催化剂载体活性位点的酸性和表面官能团、多孔和缺陷结构对催化剂性能和木质素多步转化的影响。最后,展望了木质素加氢解聚制备高附加值芳香族化学品领域未来的研究重点和发展方向。

Developing technology for the utilization of lignin resources to obtain high-value aromatic chemicals will not only increase the economic value of lignin but also help achieve the"double carbon"goal.Considerable research efforts have been directed toward investigating lignin hydrogenation.Based on the different types of hydrogen donors,lignin hydrogenation can be divided into exogenous hydrogen(including molecular hydrogen,alcohol solvents,or formic acid)and endogenous hydrogen supply(lignin self-transfer hydrogenolysis).Lignin hydrogenation offers notable advantages,such as high product yields and relatively simple product compositions.However,harsh reaction conditions have prompted the development of efficient hydrogenation catalysts.The focus of research is on regulating the active metal and support centers of hydrogenation catalysts to improve the activity.Through extensive studies of numerous lignin hydrogenation catalysts,advances in lignin hydrogenation depolymerization have been summarized.The influence of metal oxygen affinity,along with the different catalytic effects of various sizes of metal on the product distribution of lignin depolymerization through exogenous hydrogen supply and self-transfer hydrogenolysis,is analyzed.Additionally,the impacts of acidity,surface functional groups,and porous and defective structures of supports on catalytic performance are elucidated.Finally,the prospective outlook on the future of lignin resource utilization is presented.