A large number of chemical, bio-chemical and pollution-control processes use heterogeneous fixed-bed reactors. The use of finite hollow cylindrical catalyst pellets can enhance conversion levels in such reactors. The absence of the pellet core can significantly lower the diffusional resistance associated with the solid phase. This leads to a better utilization of the catalytic material, which i...

During the growth of InAs nanowires from Pd catalyst particles on InAs(111)A substrates, two distinct classes of nanowires are observed with smooth or zigzagged sidewalls. It is shown that this is related to a bimodal distribution of the wire-tip diameter: above a critical diameter wires grow with smooth sidewalls, and below with zigzagged morphology. Transmission electron microscopy analysis s...

An efficient formation of acetoin from acetaldehyde was achieved under thiazolylidene catalysis. High yields and TON were achieved. Its sufficient tolerance toward ethanol and moisture renders it a practical key step of the ethanol upgrading process. A new type of solid supported thiazolylidene catalyst was designed to make catalyst recycling achievable.

During this study the application of Natrolite zeolite was investigated as a solid acid catalyst for efficient preparation of 5substituted 1H-tetrazole derivatives. Excellent yields of products were obtained with a wide range of substrates. After completion of the reaction, the catalyst was recovered by filtration and reused several times with only a slight decrease of activity observed under t...

A systematic study of two-staged upgrading process of vacuum residue for light fuel production has been carried out in a semi-batch binary reactor apparatus over Y, ZSM-5 and alkaline treated ZSM-5 zeolites. Prepared catalyst samples were characterized with XRD and BET. Density and Viscosity physical properties parameters estimation, as well as GC/SIMDIS analyses were conducted on liquid produc...

phenytoine derivatives were synthesized , via the  pinacol condensation  with the  reaction of 1,3- diphenyl- propane- 1,3- dione (benzyl) analogs with urea or thiourea in presence of slica gel and solid KOH as Solid phase catalyst  in the mortar / pestle at room temperatures. The reaction was completed at short reaction times (approximately 15min) and pure products were obtained with high yiel...

In this work, sawdust, a biomass waste, is converted into a magnetic porous carbonaceous (MPC) solid acid catalyst by an integrated fast pyrolysis-sulfonation process. The resultant magnetic solid acid has a porous structure with high surface area of 296.4 m(2) g(-1), which can be attributed to the catalytic effect of Fe. The catalytic activity and recyclability of the solid acid catalyst are e...

An effective solid-state reaction method is reported for synthesizing boron nitride nanotubes (BNNTs) in large scale and with high purity by annealing amorphous boron powder and ferric chloride (FeCl3) catalyst in ammonia atmosphere at elevated temperatures. FeCl3 that has rarely been utilized before is introduced not only as a catalyst but also as an efficient transforming agent which converts...