platinum extraction from different secondary sources has been experimentally tested by many researchers. in this article, dissolution of platinum in aqua-regia solution from two types of spent catalysts (reforming and nitric acid production) was kinetically studied. a variety of kinetic models for heterogeneous solid-liquid reactions, including homogeneous diffusion model, shrinking core model,...

A series of new CO tolerant anode catalysts for reformate type polymer electrolyte fuel cells are proposed that are superior to state-of-the-art Pt-Ru metal alloy catalysts. Composite catalysts based on platinum and metal complex were fabricated by a new procedure where carbon supported platinum precursor and nitrogen containing organic metal complex were heat-treated in Ar atmosphere at temper...

High-energy-resolution fluorescence detection (HERFD) X-ray spectroscopy is presented as a new tool for the identification of the bonding sites of reactants in supported metal catalysts. The type of adsorption site of CO on an alumina-supported platinum catalyst and the orbitals involved in the bonding are identified. Because X-ray absorption spectroscopy (XAS) is element-specific and can be us...

Platinum-based catalysts have been considered the most effective electrocatalysts for the hydrogen evolution reaction in water splitting. However, platinum utilization in these electrocatalysts is extremely low, as the active sites are only located on the surface of the catalyst particles. Downsizing catalyst nanoparticles to single atoms is highly desirable to maximize their efficiency by util...

Reducing the noble-metal catalyst content of acid Polymer Electrolyte Membrane (PEM) water electrolyzers without compromising catalytic activity and stability is a goal of fundamental scientific interest and substantial technical importance for cost-effective hydrogen-based energy storage. This study presents nanostructured iridium nanodendrites (Ir-ND) supported on antimony doped tin oxide (AT...

A combined theoretical and experimental analysis of the electrode potential dependencies of activation energies is presented for the first step in oxygen reduction over platinum and platinum alloy catalysts in both polycrystalline and carbon supported form. Tafel data for several of the catalysts are used to predict potential-dependent activation energies for oxygen reduction over the 0.6-0.9 V...

Electrooxidation of methanol, ethanol, and formic acid was studied on three platinum-containing electrocatalysts: PtCu/C, Pt/(SnO2/C), Pt/C, Pt content being about 20 wt%. In all reactions, the integral specific activity catalysts, estimated from results cyclic voltammetry, grows in Pt/C < Pt/(SnO2/C) PtCu/C row. The influence reagent nature subjected to electrooxidation is manifested both d...

Catalysts based on zirconia and alumina-supported tungsten oxides (3–18 wt% W) with a small loading of platinum (0.3 Pt) were selected to study the influence W loading, support type, preparation methods hydroisomerization n-dodecane. The alumina- zirconia-supported catalysts show different catalytic properties that play an important role in n-dodecane conversion. Specific surface area acidity a...