MCM-41

About: MCM-41 is a research topic. Over the lifetime, 2355 publications have been published within this topic receiving 91416 citations.

Porous Silica Nanospheres Functionalized with Phosphonic Acid as Intermediate-Temperature Proton Conductors

Abstract: This paper reports the first study of developing porous silica nanospheres functionalized with phosphonic acid as intermediate-temperature (above 100 °C) proton conductors. These materials were synthesized by the co-condensation of diethylphosphatoethyltriethoxysilane (DPTS) and tetraethoxysilane using surfactant cetyltrimethylammonium bromide as a template, followed by acidification of phosphonate to phosphonic acid. With more DPTS used in the synthesis, the pore structure of the sample changes from the ordered mesoporous MCM-41 structure to the microporous structure, and the particle size simultaneously increases from ca. 80 to ca. 200 nm. The prepared silica nanospheres show promising proton conductivity above 100 °C; for example, the conductivity is as high as 3.0 × 10−4 to 0.015 S cm−1 at 130 °C when the relative humidity increases from 20 to 100%. The proton conductivity increases with an increase in the content of functionalized phosphonic acid, whereas the conductivity under low humidity condition...

Double organic modification by 3‐chloropropyl and methyl groups on pure silica MCM‐41 and Ti‐MCM‐41: efficient catalyst for epoxidation of cyclododecene

Abstract: Simultaneous surface modification by 3‐chloropropyl and methyl groups on the same Si atoms resulted in hydrophobic and highly ordered mesoporous silica with a very high surface area. 13C and 29Si MAS NMR spectra indicate homogeneous grafting of chloropropyl and methyl groups in the silica matrix and this organically modified Ti‐MCM‐41 shows outstanding catalytic performance in the epoxidation of cyclododecene using tert‐butyl hydroperoxide as oxidant.