【摘要】 为探讨钛硅原子配位结构与催化氧化活性的关系,合成了多种不同结构的钛硅材料,采用N₂低温吸附-脱附、紫外-可见光谱（UV-Vis）、紫外-拉曼光谱（UV-Raman）和红外光谱等方法表征了所合成钛硅材料的结构和Ti-Si配位结构,分别考察了其在有机过氧化物、H₂O₂参与的反应中的催化活性,并建立了初步关联。结果表明:TS-1分子筛中Ti以四角四配位钛[Ti（OSi）₄]和锐钛矿型TiO₂为主;Ti-MCM-41和Ti-SBA-15中钛物种以三角四配位钛[Ti（OH）（OSi）₃]为主;无定形TiO₂-SiO₂中五配位/六配位钛物种占优。Ti催化活化H₂O₂和有机过氧化物的能力与其配位结构密切相关,四角四配位钛在有机过氧化物和H₂O₂参与的氧化反应中均具有较好的催化活性;三角四配位钛、五配位和六配位钛物种在有机过氧化物参与的反应中表现出优异的催化活性,但难以活化H₂O₂。更多还原

【Abstract】 For titanosilicates, to better understand the relation between Ti-Si coordination and catalytic activity, various titanosilicates were synthesized and their catalytic activities were investigated through epoxidation reactions with using H₂O₂ and organic peroxide as oxidants. Characterization results of UV-Vis, UV-Raman indicate that the coordination states of titanium in TS-1 are mainly as [Ti（OSi）₄] and anatase TiO₂. For Ti-MCM-41 and Ti-SBA-15, their main structure is Ti（OH）（OSi）₃; however, amorphous TiO₂-SiO₂ is dominated in [Ti（OSi）₃OH)（H₂O）] and [Ti（OSi）₂（OH）₂（H₂O）₂]. It was also found that the catalytic activity of Ti atoms in H₂O₂ and organic peroxide participated reactions is closely related with the Ti-Si coordination. Both of H₂O₂ and organic peroxide could be activated by [Ti（OSi）₄], however, only organic peroxide could be activated by [Ti（OH）（OSi）₃], [Ti（OSi）₃OH)（H₂O）] and [Ti（OSi）₂（OH）₂（H₂O）₂]. This may be attributed to the-OH in their structure which can be combined with water and prevent them from binding with substrates, and thus difficult to deliver oxygen atoms from H₂O₂.更多还原