نتایج جستجو برای: ptbased catalysts
تعداد نتایج: 32940 فیلتر نتایج به سال:
Some of the most active catalysts for carbon dioxide and epoxide copolymerization are dinuclear metal complexes. Whilst efficient homodinuclear catalysts are known, until now heterodinuclear catalysts remain unreported. Here, a facile, in situ route to a catalyst system comprising amixture of homoand heteronuclear Zn–Mg complexes is presented. This catalyst system shows excellent polymerization...
Recently mesoporous materials have drawn great attention in fuel cell related applications, such as preparation of polymer electrolyte membranes and catalysts, hydrogen storage and purification. In this mini-review, we focus on recent developments in mesoporous electrocatalysts for polymer electrolyte membrane fuel cells, including metallic and metal-free catalysts for use as either anode or ca...
In the field of catalysis, it is highly desired to develop novel catalysts that combine the advantages of both homogeneous and heterogeneous catalysts. Here we disclose that the use of plant polyphenol as amphiphilic large molecule ligand/stabilizer allows for the preparation of noble metal complex and noble metal nanoparticle catalysts. These catalysts are found to be highly selective and acti...
The widespread use of fuel cells is currently limited by the lack of efficient and cost-effective catalysts for the oxygen reduction reaction. Iron-based non-precious metal catalysts exhibit promising activity and stability, as an alternative to state-of-the-art platinum catalysts. However, the identity of the active species in non-precious metal catalysts remains elusive, impeding the developm...
The discovery of highly active catalysts and the success of ionic liquid immobilized systems have accelerated attention to a new class of cationic metathesis catalysts. We herein report the facile syntheses of cationic ruthenium catalysts bearing bulky phosphine ligands. Simple ligand exchange using silver(i) salts of non-coordinating or weakly coordinating anions provided either PPh3 or chelat...
Pt monometallic and Pt-Co bimetallic catalysts have been prepared on single-walled carbon nanotubes (SWNT) with and without HNO3 treatment. The HNO3 treatment introduced oxygen containing groups (OCGs), which affect both the structure and activity of the catalyst. The introduction of OCGs does not affect the structure of Pt monometallic catalysts but increased the dispersion in the bimetallic c...
Simulated compounds were prepared by loading K2SO4 onto V2O5/AC catalysts. Study the effect of K2SO4 on V1/AC catalysts in the presence of low concentration SO2. Transient response techniques, TPD was carried out. The results indicated that the DeNO activity of V1/AC catalysts was decreased seriously in the early period of operation, but the deactivation was gradually diminished with SO2 adsorp...
The reaction of copper stearate with triethylaluminurn (TEAL) formed a soluble catalyst that promoted the selective hydrogenation of the linolenyl groups in soybean oil. This homogeneous catalyst was more active than copper-chromite. The activity was enhanced by the addition of silica, alumina or titania. Ethyl alcohol accelerated the hydrogenation when it was added in small amounts and retarde...
Synthesize carbon-based metal-free catalysts and • carbon-composite catalysts for oxygen reduction reaction (ORR). Optimize catalytic active reaction sites as a function • of carbon support, surface oxygen groups, nitrogen content, surface modifiers, pyrolysis temperature, porosity, and the concentration of the non-metallic additive “X” in the catalyst matrix. Evaluate catalyst stability under ...
An efficient method for the synthesis of heterogeneous gold catalysts has been developed. These catalysts were easily assembled from readily available silica materials and gold complexes. The heterogeneous catalysts exhibited superior reactivity in various reactions where protodeauration is the rate-limiting step. Dramatic enhancement in regio- and enantioselectivity was observed when compared ...
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