13 research outputs found
Catalytic behavior of Mg–Al and Zn–Al mixed oxides in the transesterification of rapeseed oil: comparison of batch and fixed bed reactors
Study of the performance of amino-functionalized ordered mesoporous carbon in the transesterification of soybean oil
Synthesis of Poly(isosorbide carbonate) via Melt Polycondensation Catalyzed by Ca/SBA-15 Solid Base
Modification of bio-hydroxyapatite generated from waste poultry bone with MgO for purifying methyl violet-laden liquids
Catalytic synthesis of biodiesel from waste cooking oil and corn oil over zirconia-based metal oxide nanocatalysts
SixC1 12xO2 alloys: A possible route to stabilize carbon-based silica-like solids?
Novel extended tetrahedral forms Of CO2 have been synthesized recently under high-pressure conditions. We perform ab initio density functional theory calculations to investigate whether doping with Si can extend the stability range of such tetrahedral forms Of CO2 to ambient pressure. Calculations are performed with a simple cubic cell containing eight formula units in alpha-cristobalite-like structure. Though we find that all the SiC1-xO2 structures considered by us are thermodynamically unstable with respect to decomposition into the end members at ambient pressures, the energy differences are small, suggesting that it might be possible for such phases to exist in metastable forms. At higher pressures, the heat of formation is found to be negative. The bonding between C and O atoms is more covalent than that between Si and 0 atoms. We also find indications that some C atoms may prefer three-fold coordination at low pressur