Pt impregnated on a Sn-beta catalyst results in a very promising catalyst for the selective hydrogenation of α,β-unsaturated aldehydes, compared to the PtSn co-impregnated beta catalysts. Framework tin ions in the Sn-beta sample stabilize the nucleation of platinum nanoparticles inside the zeolite channel. These Pt(0)-Sn(4+) sites, which are only observed in the Pt/Sn-beta catalyst, have been s...

in this study, we describe the growth of carbon nanotubes on commercial iron nanoparticles without carbon shell (fe (nm), size 2o3 and fe* (nm)/mgo) was carried out by mixing commercial fe* nanoparticles (as catalyst) with al2o3 and mgo powders (as supports)by using ball-milling method. the results show in spite of the fact that ball-milling process can have negative effects on diameter and mor...

The identification of the active sites in heterogeneous catalysis requires a combination of surface sensitive methods and reactivity studies. We determined the active site for hydrogen evolution, a reaction catalyzed by precious metals, on nanoparticulate molybdenum disulfide (MoS2) by atomically resolving the surface of this catalyst before measuring electrochemical activity in solution. By pr...

The long-term efficiency of proton exchange membrane fuel cells (PEMFC) is largely restricted by the instability of catalyst nanoparticles during fuel cell operation. Due to their large surface area-tovolume ratio, Pt and Pt-alloy nanoparticles have a strong tendency to grow in size over short time scales, which lead to a reduction in their electrochemically-active surface area, and consequentl...

the reaction of 3-chloropropyl boehmite nanoparticles with caffeine and sulfuric acid afforded bnps-3-propyl-imidazolopyridinium hydrogen sulfate [bnps-caff]hso4 as a new bnps-supported ionic liquid (il) catalyst. [bnps-caff]hso4 proved to be an efficient heterogeneous catalyst for the synthesis of pyrazolopyranopyrimidines via a one-pot four-component reaction of hydrazine hydrate, ethyl aceto...

The authors experimentally demonstrate a simple and efficient approach for nucleating the catalytic chemical vapor deposition CVD growth of GaN nanowires, Ga2O3 nanowires, and Ga2O3 nanoribbons by using ion implantation of Fe+ into thermally grown SiO2 layers and subsequent annealing to form the catalyst nanoparticles. This work shows that ion implantation can be used as a versatile method to c...

Three kinds of HZSM-5 nanoparticles with different acidity were tailored by impregnating MgO or varying Si/Al ratios. Both the textural and acidic properties of the as-prepared nanoparticles were characterized by nitrogen adsorption-desorption measurements, X-ray diffraction (XRD), scanning electron microscopy (SEM), ammonia temperature-programmed desorption (NH3-TPD) and Fourier transform infr...

A new efficient heterogeneous catalyst was introduced for the epoxidation of styrene. The catalyst was obtained from functionalization of cellulose with N-(2-aminoethyl)acetamide, and then deposition of nanoparticles and Pd(0) nanoparticles on the modified cellulose. The Fe3O4 nanoparticles were deposited via chemical oxidation in basic media and Pd(0) nanoparticles we...

The preparation of FSG-supported palladium nanoparticles and their application in direct C-2 arylation of indoles are presented. Moderate to good yields were obtained with ultra-low catalyst loading. The catalyst could be easily recovered by simple workup and reused up to seven runs with only a slight decrease in its activity.

Core/shell nanostructured carbon materials with carbon nanofiber (CNF) as the core and a nitrogen (N)-doped graphitic layer as the shell were synthesized by pyrolysis of CNF/polyaniline (CNF/PANI) composites prepared by in situ polymerization of aniline on CNFs. High-resolution transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared and Raman analyses indicat...