Cerium Incorporated Into a Mesoporous Molecular Sieve (Mcm-41)

Abstract

-The synthesis and characterization of a mesoporous molecular sieve (MCM-41) was studied due to its high surface area and large pore volume and to target potential applications in adsorption and catalysis. Rare earth elements have special chemical properties and are efficient promoters for supports. In this study, a mesoporous molecular sieve that incorporates the transition metal cerium (Ce-MCM-41) was synthesized using the hydrothermal method with the goal of improving the structural properties for adsorption. The molar composition of the obtained gel was 1CTMABr: 4SiO2: 1Na2O: 0.2Ce2O3: 200H2O. The pure mesoporous molecular sieve MCM-41 was also synthesized using the same method. The materials were characterized by the following techniques: XRD, BET/BJH, SEM/EDS, TG and FT-IR. A preliminary test to evaluate the materials as adsorbents to remove naphthenic acids present in jet fuel was performed. The results of the characterization showed that the incorporation of the metal cerium did not affect the MCM-41 structure and that mesporous materials were formed. Ce-MCM-41 exhibited good thermal stability, high specific surface area and large pore volume, which are characteristics of a good adsorbent. From the preliminary test, the adsorptive capacity increased by 60% with the incorporation of cerium in the MCM-41 structure.

Br-doped Ga2O3/MCM-41 catalyzed synthesis of propylene carbonate from carbon dioxide and propylene oxide

“…2a reveals a prominent diffraction peak (100) at 2 θ = 2.17°, along with two weaker peaks (110) and (200) at 3.69° and 4.27°, characteristic of MCM-41. 46 Following the loading of Ga 2 O 3 onto MCM-41, a shift of the MCM-41 diffraction peak towards lower angles is observed. This shift could be attributed to the larger atomic radius of Ga compared to Si, suggesting the doping of Ga atoms into the SiO 2 framework of MCM-41.…”

Bimetallic NiCe/Lay catalysts facilitated co-pyrolysis of oleic acid and methanol for efficiently preparing anaerobic hydrocarbon fuels

“…As seen in the figure, increasing the catalyst dose from 0.5 to 1 g enhanced the selectivity of hydrocarbons in the products due to the increase in catalyst, which increased the number of active sites participating in the reaction. 77 However, the hydrocarbon selectivity decreased instead with a further increase in the catalyst dosage. This may be due to the fact that some active sites were shielded due to carbon accumulation and agglomeration of catalysts at high temperatures during the catalytic process, which resulted in fewer catalysts actually participating in the catalysis and thus affecting the catalytic effect.…”