钨基固体酸中WOx亚纳米团簇Brønsted酸位点的构建及调控

固体酸催化是酸催化领域的重要研究方向，但传统的固体酸催化剂酸密度低、稳定性差、成本较高且催化性能不佳。本项目利用三种方法制备WO3-ZrO2复合过渡金属氧化物固体Brønsted酸催化剂，创新性地借助氨气−空气分段焙烧诱导的表面氮化法，可控调节含N原子的WOx亚纳米团簇活性位点进而逆增锆钨固体酸催化性能，并以苯甲醇和苯甲醚傅克烷基化反应为探针反应，探明酸性活性中心产生规律及微观结构调控机制。此外，项目还将表面氮化法推广应用于合成其他含W复合过渡金属氧化物体系，拓展该新技术逆增固体酸催化活性的通用性，最终实现固体强酸催化剂的高效低成本制备。申请人将阐明W基固体酸催化剂活性中心分子的“组成−结构−酸催化性能”构效关系，揭示表面氮化法逆增固体酸催化材料酸性的微观机制，为开发新一代固体Brønsted酸催化材料提供新思路，开辟新途径。

Solid acid catalysts (SACs) play a vital role in modern acid catalysis, while traditional SACs perform worse than expected due to their low acidity density, poor thermal stability and high manufacturing cost. In this project, we plan to synthesize WO3-ZrO2 transitional metal oxides based Brønsted SACs via three methods, whose acidity can be greatly enhanced by successive ammonia gas (NH3) and air treatment at high temperatures. This unique preparation method is supposed to induce surface nitridation of SACs by controlled generation of rich WOx sub-nano clusters active sites involving N atoms. Based on the solid NMR, XPS, HR-TEM, HAADF-STEM and other characterization results, we chose Friedel-Crafts reaction of anisole and benzyl alcohol as a probe reaction to determine structure-activity relationship between the WOx sub-nano clusters and catalytic activity of surface modified SACs. It is expected that the present ammonia-air treatment induced nitridation technique can be used in the synthesis of a variety of hybrid transition metal oxides SACs containing tungsten to expand its universality, and that the outcome of this proposal will have immediate practical implications and advantages for designing new generation of Brønsted SACs.