A 40 wt% Pt/C cathode electrocatalyst with controlled Pt particle size of approximately 2.9 nm showing better performance than commercial catalyst for direct methanol fuel cell was prepared by a polyol process with water but without using stabilizing agent.

A triethylaluminium(TEAl)-modified Phillips ethylene polymerisation Cr/Ti/SiO2 catalyst has been developed with two distinct active regions positioned respectively in the inner core and outer shell of the catalyst particle. DRIFTS, EPR, UV-Vis-NIR DRS, STXM, SEM-EDX and GPC-IR studies revealed that the catalyst produces simultaneously two different polymers, i.e., low molecular weight linear-ch...

in our previous work, the effect of use of a water soluble cdi/nhs system as nontoxic cross-linking agent on fabrication of gelatin nanoparticles was investigated. in this research, the effect of variation in some synthetic parameters of gelatin nanoparticles cross-linked by cdi/nhs system such as type of gelatin and formulation of cross- linking agent on their size and distribution was examine...

Electromagnetic and heat transfer analysis is used to determine possibility of selective heating of nanometer-sized, metallic catalyst particles attached to a ceramic support through microwave irradiation. This analysis is incorporated into a macroscopic heat transfer model of a packed and fluidized catalyst bed heated by a microwave field to predict thermal effects associated with selective he...

Transmission electron microscopy is the state-of the art technique for the study of particle size and size distribution in model catalyst systems. We have investigated platinum nanoparticles supported on glassy carbon. Our novel approach was to vary the size of nanoparticles allowing us to produce particles in the range 1 to 5 nm with a very narrow size distribution. To avoid the problems arisi...

The control over both the dispersion and the particle size distribution of supported precious metal nanoparticles used in heterogeneous catalysts is of paramount importance. Here, we demonstrate the successful formation of highly accessible and well dispersed gold−palladium nanoparticles, stabilized with two-dimensional graphene oxide, that itself is dispersed by intercalated titania particles ...

Rh/γ-Al₂O₃ catalysts were synthesized by both incipient wetness impregnation (IWI) and atomic layer deposition (ALD). The TEM images of the two catalysts showed that the catalyst from ALD had smaller particle size, and narrower size distribution. The surface chemical states of both catalysts were investigated by both XPS and X-ray Absorption Near Edge Structure (XANES), and the catalyst from IW...

in this study, a manganite sample with a nominal formula of la0.9sr0.1mno3 was prepared by the microwave assisted sol-gel method and annealing at various temperatures. the structural and magnetic properties of the samples were investigated by xrd, fesem and ac susceptometer, respectively. xrd analysis showed that the samples are a nearly single phase. fesem micrographs showed that by increasing...

in order to ensure the safety of parenterals, international pharmacopoeias and national standards have set up stringent guidelines and standards. particulate con- tamination is a potential health risk caused by intravenous injection of particles large enough to potentially clog the small arteries. particles could be produced through manufacturing and packaging or even dispensing of the pharmace...

Spontaneous spatiotemporal wave activity occurs in groups of excitable particles for groups larger than a critical size. Experiments are carried out with particles loaded with the catalyst of the Belousov-Zhabotinsky reaction that are immersed in catalyst-free reaction mixture. The particles diffusively exchange activator and inhibitor species with the surrounding solution. All particles are no...