Synthesis of imidazo[1,2-a]pyridines over several solid supported catalysts has been investigated. Among these catalysts, ZnCl2 .SiO2 (silzic) showed excellent yields and short reaction times. The silzic catalyst could be recovered and reused in five reaction cycles. The present procedure offers several advantages such as short reaction time, simplicity of the reaction procedure, the eliminatio...

A kinetic study of vinyl acetate (VA) synthesis over a Pd(100) catalyst is described, and the effect of particle-size on this reaction ascertained by comparing the single crystal data with data from supported Pd catalysts (5 wt% Pd/SiO2, dPd=4.2 nm, and 1 wt% Pd/SiO2, dPd=2.5 nm). A negative reaction order with respect to ethylene and a positive order with respect to oxygen were found for the m...

The literature of olefin metathesis by heterogeneous supported catalysts, both industrial-type supported metal oxides (ReOx/Al2O3, ReOx/(SiO2−Al2O3), MoOx/SiO2, MoOx/Al2O3, MoOx/(SiO2−Al2O3), WOx/SiO2, and WOx/ (SiO2−Al2O3)) and supported organometallic complexes, is comprehensively reviewed. The focus of this Review is supported metal oxide catalysts, but the well-defined supported organometal...

Supported metal oxide based olefin metathesis catalysts are widely used in the chemical industry. In comparison to their organometallic catalyst cousins, the oxide catalysts have much lower activity due to the very small fraction of active sites. We report that a simple pretreatment of MoO3/SiO2 and WO3/SiO2 under an olefincontaining atmosphere at elevated temperatures leads to a 100−1000fold i...

Conventional supported Pt catalysts have often been prepared by loading Pt onto commercial supports, such as SiO2, TiO2, Al2O3, and carbon. These catalysts usually have simple metal-support (i.e., Pt-SiO2) interfaces. To tune the catalytic performance of supported Pt catalysts, it is desirable to modify the metal-support interfaces by incorporating an oxide additive into the catalyst formula. H...

Iron containing nanoparticles are found to spontaneously form on hydroxylated SiO2 substrates when immersed in a freshly mixed aqueous solution of FeCl3 and hydroxylamine. Upon calcination, a submonolayer of uniformly distributed iron oxide nanoparticles can be derived and used to catalyze the growth of single-walled carbon nanotubes by chemical vapor deposition. This simple method affords clea...

The hydrogenation of crotonaldehyde in the presence of supported platinum nanoparticles was used to determine how the interaction between the metal particles and their support can control catalytic performance. Using gas-phase catalytic reaction studies and in situ sum-frequency generation vibrational spectroscopy (SFG) to study Pt/TiO2 and Pt/SiO2 catalysts, a unique reaction pathway was ident...

In situ Raman spectroscopy is rapidly becoming a very popular catalyst characterization method because Raman cells are being designed that can combine in situ molecular characterization studies with simultaneous fundamental quantitative kinetic studies. The dynamic nature of catalyst surfaces requires that both sets of information be obtained for a complete fundamental understanding of catalyti...

An ultrathin poly(tetrafluoroethylene) (PTFE)-reinforced multilayer self-humidifying composite membrane (20 microm, thick) is developed. The membrane is composed of Nafion-impregnated porous PTFE composite as the central layer, and SiO2 supported nanosized Pt particles (Pt-SiO2) imbedded into the Nafion as the two side layers. The proton exchange membrane (PEM) fuel cell employing the self-humi...

Substituted pyrroles are an essential class of heterocyclic compounds. In this research, an efficient and eco-friendly method has been developed for the synthesis of pyrrole derivatives from the reaction of 2,5-hexanedione and primary amines. Magnetic nanoparticles supported on functionalized. 7-aminonaphthalene-1,3-disulfonic acid-functionalized. silica (Fe3O4@SiO2@Propyl–ANDSA) has been inves...