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N 2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、H 2O 2参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TiO 2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TiO 2-SiO 2中五配位/六配位钛物种占优。Ti催化活化H 2O 2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H 2O 2参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H 2O 2。
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 H 2O 2 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 TiO 2.For Ti-MCM-41 and Ti-SBA-15,their main structure is Ti(OH)(OSi)3;however,amorphous TiO 2-SiO 2 is dominated in[Ti(OSi)3OH)(H 2O)]and[Ti(OSi)2(OH)2(H 2O)2].It was also found that the catalytic activity of Ti atoms in H 2O 2 and organic peroxide participated reactions is closely related with the Ti-Si coordination.Both of H 2O 2 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)(H 2O)]and[Ti(OSi)2(OH)2(H 2O)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 H 2O 2.
作者
张耀
夏长久
彭欣欣
林民
朱斌
段庆华
罗一斌
舒兴田
ZHANG Yao;XIA Changjiu;PENG Xinxin;LIN Min;ZHU Bin;DUAN Qinghua;LUO Yibin;SHU Xingtian(Research Institute of Petroleum Processing,SINOPEC,Beijing 100083,China)
出处
《石油学报（石油加工）》
EI
CAS
CSCD
北大核心
2019年第5期860-867,共8页
Acta Petrolei Sinica(Petroleum Processing Section)
基金
国家重点研发计划项目(2017YFB0306800)基金资助
