a kinetic-spectrophotometric procedure is reported for determination of trace amounts of ag(i). this method is based on catalytic effect of silver ion on the oxidation of congo red by potassium peroxodisulphate at ph=3.4 and 30 oc in the presence of 1,10-phenanthroline as an activator. the reaction was followed spectrophotometrically by measuring the rate of change in absorbance of congo red at...

a catalytic-kinetic method for the determination of selenium is proposed. alizarin navy blue is reduced by sodium sulfide to from a colorless product. the reaction is accelerated by trace amounts of se (iv), and can be followed by measuring the decrease in absorbance of the dye at 620nm and 30 °c by the fixed time method. selenium can be determined in the range of 0.004 — 0.12 1.1g.m1-1 . ...

The high catalytic activity of gold clusters on oxides has been attributed to structural effects (including particle thickness and shape and metal oxidation state), as well as to support effects. We have created well-ordered gold mono-layers and bilayers that completely wet (cover) the oxide support, thus eliminating particle shape and direct support effects. High-resolution electron energy los...

in the present study, the effects of calcium doping on the performance of the co-precipitated cu-mgo catalysts prepared with different calcium loadings in the selective hydrogenation of furfuraldehyde were investigated. the results proved that the addition of this promoter had a remarkable impact on the catalytic performance. the conversion of furfuraldehyde enhanced up to 83% and the furfuryl ...

The Pd-catalyzed hydrogenation of anthraquinone to synthesize hydrogen peroxide is an important process in the chemical industry. A Pd catalyst with high dispersion key activity and selectivity. For first time, this team introduced AlPO-5 zeolite SiO2 powder prepare a finely dispersed higher efficiency than conventional Pd/SiO2 catalyst. Based on previous research, other aluminophosphate molecu...

background diatomite coated by nanoparticles of copper and zinc mixed oxides were used to investigate catalytic oxidation of carbon monoxide. objectives aim of this paper was to investigatediatomite performance as a supporting host to confine the cuo and zno nanoparticles and its catalytic activity for carbon monoxide oxidation. materials and methods the prepared catalysts were characterized by...

Recent progress on oxide-based thermo-photocatalytic composite systems. Role of plasmonic, defect-related, and thermal effects the catalytic performance.

in the present work, the modified nickel electrode was electrochemically fabricated and tested for the electro-oxidation of paracetamol in alkaline media. the methods of cyclic voltammetry (cv), chronoamperometry (ca), and impedance spectroscopy (eis) were used to determine kinetic parameters such as transfer coefficient (α), the catalytic reaction rate constants (k), and the diffusion coeffici...

a catalytic spectrophotometric method for determination of ultra-trace quantities of manganese(ii) id described. the method is based on the catalytic effect of manganese(ii) on the oxidation reaction of ferroin by potassium periodate in acidic media. the reaction is monitored spectrophotometrically at 510 nm by a slope method and mn(ii) is determinable in the range of 1-1000ngml-1. the limit of...