the interaction of the external donor (propyltrimethoxysilane - ptms) with titanium-magnesium catalysts (tmcs) containing dibutylphthalate (dbp) as internal donor, which were prepared in different ways, was studied by chemical analysis and infrared diffuse reflectance spectroscopy (drifts). the chemical composition of the catalysts after their interaction with heptane solutions of ptms, ptms/al...

Heterogeneous catalysts are promising for the transesterification reaction of vegetable oils to produce biodiesel and have been studied intensively over the last decade. Unlike the homogeneous catalysts, heterogeneous catalysts can be easily separated from reaction mixture and reused for many times. They are environmentally benign and could be easily operated in continuous processes. This revie...

carbon nanotubes were synthesized over a series of zn-containing fe/alumina catalysts by chemical vapor deposition method at two reaction temperatures of 850 and 950 °c using methane as a carbon source. catalysts were synthesized by keeping fe concentration constant and varying zn concentration to study the effects of zn. the catalysts were characterized using x – ray powder diffraction and n2 ...

h-zsm-5 nano-zeolites were synthesized by hydrothermal method using tetrapropylammonium hydroxide (tpaoh) as a template in the presence of various tpabr concentrations. the effect of different tpabr/tpaoh molar ratios was studied on the catalytic performance of dehydration of methanol to dimethyl ether (dme) in a fixed bed reactor under the same operating conditions (t=300°c, p=1 atm, and whsv=...

Tungstate-catalyzed hydrogenolysis of sugars in untreated woody biomass to ethylene glycol (EG) has so far been unsuccessful. This work shows that production EG is predominantly hampered by the presence inorganic impurities biomass, which can be selectively removed an acid leaching step at room temperature. Catalytic and acid-leached samples was run 245 °C using sodium polytungstate Raney Ni ca...

Abstract A series of aryl sulfonic acids were tested as catalysts for acid hydrolysis occurring at the surface poly(ethylene) terephthalate (PET) particles. Specifically, p‐toluenesulfonic monohydrate (PTSA), 2‐naphthalenesulfonic (2‐NSA), and 1,5‐naphthalenedisulfonic tetrahydrate (1,5‐NDSA) chosen to provide active groups varying hydrophobic functionality. The effect catalyst concentration re...

Catalysts are important to the chemical industry and environmental remediation due to their effective conversion of one chemical into another. Among them, composite catalysts have attracted continuous attention during the past decades. Nowadays, composite catalysts are being used more and more to meet the practical catalytic performance requirements in the chemical industry of high activity, hi...