Ti-HMS (hexagonal mesoporous silica, HMS) was vapor silylated at 150–450°C. The samples were characterized by Si29 CP/MAS NMR, FTIR, TG, XRD, and N2-adsorption, respectively, as well as evaluated by the continuous epoxidation of propylene with cumene hydroperoxide (CHP) as oxidant. There showed only a peak at 14 ppm assigned to (CH3)3Si*OSi(OSi)3 species in NMR spectra when silylated at low temperatures. The samples at higher temperatures (>250°C) gave an additional peak at 20 ppm, which was assigned to novel titanium species of (CH3)3Si*OTi(OSi)3. The intensity of peaks relevant to trimethyl groups increased with the silylation temperature at 150–350°C and decreased at 350–450°C due to decomposing of organic groups. The intensity reached the highest point at 350°C. The catalytic results showed that the propylene oxide yield also changed as the same trend and reached the longest life of 100% PO yield at 350°C silylation. In conclusion, 350°C is an optimal silylation temperature.
Russian Journal of Applied Chemistry – Springer Journals
Published: Feb 9, 2017
It’s your single place to instantly
discover and read the research
that matters to you.
Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.
All for just $49/month
Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly
Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.
All the latest content is available, no embargo periods.
“Whoa! It’s like Spotify but for academic articles.”@Phil_Robichaud