0000000000311199
AUTHOR
S. Hernández
Oxidative dehydrogenation of ethane over NiO–CeO2 mixed oxides catalysts
[EN] In this paper we present the synthesis, characterization and catalytic behaviour in the oxidative dehydrogenation of ethane of NiO-CeO2 mixed oxides. The addition of cerium oxide to NiO strongly modifies its catalytic performance, although the changes in the catalytic behaviour depend on the catalyst composition. The incorporation of low amounts of cerium oxide to NiO multiplies the productivity to ethylene in the oxidative dehydrogenation of ethane by a factor of ca. 7, which is the result of an increase in both catalytic activity and selectivity to ethylene. The enhanced activity has been related to the remarkable increase of the surface area of catalyst and the low crystal sizes of …
Influence of gel composition in the synthesis of MoVTeNb catalysts over their catalytic performance in partial propane and propylene oxidation
[EN] MoVTeNb mixed oxides catalysts have been prepared by a slurry method with different molar compositions (Mo/Te ratio from 2 to 6 and Nb/(V + Nb) ratio from 0 to 0.7) in the synthesis gel leading to different crystalline phases distribution and catalytic behaviour in the partial oxidation of both propane and propylene to acrylic acid. Chemical analysis indicates that the composition of samples before and after the heat-treatment changes, especially the Te-content, since a significant amount of Te is lost during the heat-treatment step when the amount of oxalate (from niobium oxalate) increases in the synthesis gel. Thus, the nature of the crystalline phases and the catalytic performance …
Selective oxidative dehydrogenation of ethane over SnO2-promoted NiO catalysts
[EN] Ni-Sn-O mixed oxides catalysts have been investigated for the oxidative dehydrogenation of ethane. The catalysts were prepared through the evaporation of aqueous solutions of nickel nitrate and tin oxalate and finally calcined in air at 500 degrees C for 2 h. These materials have been characterized by several techniques (N-2-adsorption, X-ray diffraction, High-Resolution Electron Microscopy, temperature programmed reduction, X-Ray Photoelectron Spectroscopy, Fourier Transformed Infrared Spectroscopy of adsorbed CO and O-18/O-16 isotope exchange). The addition of just a tiny amount of tin highly increases the selectivity to ethylene (from ca. 40% to 80-90%). Thus, high selectivity to et…