钙钛矿复合氧化物合成过程调控及其催化氧化木质素的构效关系

Due to the complex and stable of polymer structure, lignin was difficult to be converted to compounds with small molecule. A new method, named phenolic compounds produced from lignin under the selective catalytic oxidation of perovskite complex oxides, was proposed. The regulation of crystal phase, grain size and pore structure of perovskite oxides were explored in the preparation process. The distribution of gas, liquid and solid products was investigated for revealing the structure-function relationship between the perovskite oxides and the selective catalytic oxidation of lignin. Based on the composition analyzes of three phase products, combined with the kinetics data and the variation of metal valence, the selective breakage pathway of C-O bond for producing phenolic compounds from lignin. Moreover, the reaction mechanism of phenolic compounds produced from the selective catalytic oxidation of lignin and the regeneration regulation were obtained. It provided theoretical foundation for the production of phenolic compounds from the selective catalytic oxidation of lignin.

针对木质素高分子结构比较复杂和稳定，现有技术转化率较低等瓶颈问题，本项目提出了利用钙钛矿复合氧化物选择性催化氧化木质素的新方法并用于制取酚类化合物。通过制备过程调控，探索钙钛矿类金属氧化物晶型、晶粒尺寸和孔结构的调控方法；通过研究钙钛矿氧化物对木质素选择性氧化的催化作用及反应过程气液固产物分配规律，揭示钙钛矿氧化物与木质素选择性催化氧化之间的构效关系，通过三相产物组成分析，结合动力学数据和催化剂反应前后晶型、金属赋存价态变化，明晰木质素催化氧化制取酚类化合物中木质素C-O键选择性断裂途径，获得木质素催化氧化制取酚类化合物的反应机理和催化剂再生机制，为木质素选择性催化氧化制取酚类化学品提供理论基础和技术支撑。

本项目针对钙钛矿氧离子传递性能不易调控等瓶颈问题，通过对氧载体和钙钛矿的合成过程控制，借助空间位阻效应与外场强化作用，达到钙钛矿类金属氧化物晶型、晶粒尺寸和孔结构调控的目的，同时探究了钙钛矿复合氧化物催化氧化木质素的作用机理和再生机制，解决了钙钛矿复合氧化物晶格氧传递控制难、木质素催化热解过程传质效果差等难题。通过采用高效氧载体合成新策略，以金属硝酸盐为原料，加入沉淀剂，经水热反应后，获得晶格氧含量高的氧载体；通过改变钙钛矿的组成，实现氧离子传的调控；通过空间位阻作用与外场强化的协同耦合作用，对钙钛矿复合氧化物的合成过程进行调控，探究了钙钛矿与氧载体之间的相扩散和晶格氧传递机制；通过对木质素进行催化氧化，揭示了钙钛矿复合氧化物催化氧化木质素构效关系以及再生-循环使用机制。