Cerium modified MCM-41 nanocomposite materials via a nonhydrothermal direct method at room temperature

Synthesis, characterization and properties of anti-sintering nickel incorporated MCM-41 methanation catalysts

“…1 (bottom), the bands at 3435 cm À1 were assigned to the vibration of the Si-OH and adsorbed water molecules [14] in the spectrum for the calcined MCM-41. The bands at 1238 cm À1 , 1083 cm À1 and 808 cm À1 were assignable for the stretching vibration of the Si-O-Si; the band at 966 cm À1 was from vibration of Si-OH; the band at 463 cm À1 was assignable for the scissoring vibration of Si-O-Si [16]. In the spectrum for the calcined 4%Ni-M, similar groups of vibration bands were observed.…”

“…This indicated that the template surfactant was completely removed by calcination at 550°C for 6 h. Comparing the FTIR spectrum of calcined MCM-41, it could be found that little shift toward smaller wavenumbers of the 3435, and 1638 cm À1 bands were recognized for that of the calcined 4%Ni-M, which can be taken as an indication for the insertion of Ni 2+ in the framework of MCM-41 materials [16]. In addition, for the 966 cm À1 band, there was a change in the intensity, indicating structural change for the surface Si-OH group caused by the presence of NiO species in MCM-41, and/or due to evolution of a new band of Si-O-Ni, and manifest at the same position [17].…”

“…The bands at 1467 cm À1 , 2925 cm À1 and 2853 cm À1 were assigned the vibration of surfactant alkyl chain [15]. The bands at 1638 cm À1 were assigned to bending vibration of the adsorbed water molecules [16]. As shown below for the calcined materials of MCM-41, the bands observed below 1400 cm À1 were assigned to the framework vibration of MCM-41.…”

Preparation of MCM-41 incorporated with lacunary Keggin polyoxometalate and its catalytic performance in esterification

“…The samples used for comparison purpose were synthesized by the method based on the previously reported procedure [20] as follows: MCM-41 (1.0 g) was dispersed into ethanol (25 mL), and then the pH was adjusted to 2.0 by concentrated hydrochloric acid. Afterward, CTA-LPOM (0.14 g) was dissolved in a small amount of CH 3 CN and was added into the dispersion system prepared above and stirred for 3 h at 50°C.…”

Effect of the cerium loading on the HMS structure. Preparation, characterization and catalytic properties

“…In particular, cerium containing MCM-41 material has been used for many catalytic applications [7,8]. The cerium incorporation into the mesoporous silica network or the adding of its oxides on the surface makes a mesoporous material a bifunctional catalyst in heterogeneous acid as well as redox catalysis.…”