Oxidative activation of light alkanes on dense ionic oxygen conducting membranes

The oxidative dehydrogenation of ethane to ethylene (ODHE) has been studied in a catalytic membrane reactor (CMR) using a dense mixed ionic oxygen and electronic conducting perovskite membrane Ba0.5Sr0.5Co0.8Fe0.2O3-&. At 1080K, an ethylene yield of 66% was obtained with the bare membrane. After Pd cluster deposition, the ethylene yield reached 76% at 1050K. Ni cluster deposition led to a decrease of ethane conversion compared to the bare membrane without changing ethylene selectivity.

Hydrothermal stability and catalytic activity of aluminum-containing mesoporous ethane-silicas

Aluminum was incorporated into the mesoporous framework of ethane-silica by one-pot condensation of Al(OiPr)(3) with 1,2-bis(trimethoxysilyl)ethane using octadecyltrimethylammonium chloride as surfactant. Powder X-ray diffraction patterns, nitrogen sorption analysis, and TEM results reveal the formation of an ordered mesoporous material with uniform porosity. Al-27 MAS NMR confirms the incorporation of aluminum in the framework. The synthesized materials exhibit extremely high hydrothermal stability in boiling water (no obvious change of mesostructure and textural properties was observed even after refluxing in water for 100 h), which could be mainly contributed to the ethane-bridged mesoporous framework. The aluminum-containing mesoporous ethane-silicas are efficient catalysts for the alkylation of 2,4-di-tert-butylphenol by cinnamyl alcohol to yield a flavan.

Correlation between the characteristics and catalytic performance of Ni-V-O catalysts in oxidative dehydrogenation of propane

Ni - V - O series catalysts for the oxidative dehydrogenation (ODH) of propane were prepared and characterized by BET, XRD, H-2- TPR, O-2-TPD-MS and electrical conductivity. At 425 degreesC a C3H6 selectivity of 49.9% was observed on Ni0.9V0.1OY at a C3H8 conversion of 19.4%, and the obtained selectivity is almost two times higher than that over NiO at the roughly same conversion of C3H8. The mobile oxygen species created by the interaction of NiO and V2O5 has been found in the composite catalysts by O-2-TPD-MS and electrical conductivity studies, which seems to be responsible for the enhanced selectivity of the propane oxidative dehydrogenation.

Oxidative dehydrogenation of propane in a dense tubular membrane reactor

Oxidative dehydrogenation of propane (ODP) to propylene was investigated in a dense tubular membrane reactor made of Ba0.5Sr0.5Co0.8Fe0.2O3-delta (BSCF) at 700degreesC and 750degreesC. The propylene selectivity in the membrane reactor (44.2%) is much higher than that in the fixed-bed reactor (15%) at the similar propane conversion (23-27%). Higher propylene selectivity in the membrane reactor was attributed to the lattice oxygen (O2-) supplied through the membrane.

Mn-containing AlPO-11 and SAPO-11 catalysts for simultaneous isomerization and dehydrogenation of n-butane

MnAPO-11 and MnAPSO-11 were synthesized hydrothermally, and supported Mn-AlPO-11 and Mn-SAPO-11 were also prepared for comparison. Characterization results showed that there were differences in acidity and reducibility caused by the different incorporation methods of manganese. The manganese species in the samples also weakened the metallic properties of the palladium particles when the latter was added into the catalysts. Catalytic testing results for dehydroisomerization of n-butane indicated that incorporation of manganese increased the selectivity toward isomerization products. The highest isobutene selectivity (34.86%) could be obtained over a Pd/MnAPO-11 catalyst. When a combined catalyst system containing Pd/SAPO-11 and MnAPSO-11 was used in a single bed of two layers, the isobutene selectivity could be greatly improved, as compared to the single catalyst alone.