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Abstract  

Catalytic activity of gamma irradiated catalase from bovine liver was studied for hydrogen peroxide decomposition at constant temperature and pressure. The measurement was performed at temperatures 27, 32, 37, 42 and 47 °C. Solutions containing 1 and 0.01 g dm−3 of catalase in phosphate buffer were used for the study. Repeatability of both sample preparation and kinetics measurement was experimentally verified. Rate constants of the reaction were determined for all temperatures and the activation energy was evaluated from Arrhenius plot. Gamma irradiation was performed using 60Co radionuclide source Gammacell 220 at two different dose rates 5.5 and 70 Gy h−1, with doses ranging from 10 to 1000 Gy. The observed reaction of irradiated and non-irradiated catalase with hydrogen peroxide is of the first order. Irradiation significantly decreases catalytic activity of catalase, but the activation energy does not depend markedly on the dose. The effect of irradiation is more significant at higher dose rate.

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metalloporphyrins, could remarkably improve the catalytic activity and selectivity of metalloporphyrins in the alkene oxidation reaction [ 15 , 16 ]. Except for the axial ligands, the metal centers and the substitutional groups around porphyrin rings have a great

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diameter about 5 μm in a ternary P123-H 2 O-HCl-TEOS system were prepared by the hydrothermal method. The physical properties of the prepared Ti-containing SBA-15 samples were investigated and the catalytic activity in the epoxidation of cyclohexene was

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was also evaluated to correlate their porous characteristic and platinum dispersion with catalytic activity. Experimental Preparation of catalysts Four silicas were used in the preparation of platinum

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parameters on the activity of Ru/AC for bromate reduction up to now. In the present work, the effects of Ru precursor, Ru loading and calcination conditions on the catalytic activities of Ru/AC catalyst for bromate reduction were systematically

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A calorimetric method is proposed to evaluate the catalytic activity of a solid catalyst with respect to the exothermic oxidation of Volatile Organic Compounds (VOC).

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Abstract  

Orthorhombic structural perovskite NdCrO3 nanocrystals with size of 60 nm were prepared by microemulsion method, and characterized by XRD, TEM, HRTEM, SEM, EDS and BET. The catalytic effect of the NdCrO3 for thermal decomposition of ammonium perchlorate (AP) was investigated by DSC and TG-MS. The results revealed that the NdCrO3 nanoparticles had effective catalysis on the thermal decomposition of AP. Adding 2% of NdCrO3 nanoparticles to AP decreased the temperature of thermal decomposition by 87° and increased the heat of decomposition from 590 to 1073 J g−1. Gaseous products of thermal decomposition of AP were NH3, H2O, O2, HCl, N2O, NO, NO2 and Cl2. The mechanism of catalytic action was based on the presence of superoxide ion O2 on the surface of NdCrO3, and the difference of thermal decomposition of AP with 2% of NdCrO3 and pure AP was mainly caused by the different extent of oxidation of ammonium.

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Schiff base complexes, Mn(III), Co(II), and Cr(III) complexes have gained prominence because of their catalytic activities for a variety of oxidative organic transformations in the presence of hydrogen peroxide or organic peroxides both in homogeneous and

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expected to improve the catalytic activity and stability [ 7 , 12 ]. For example, manganese (or other promoters such as gallium, yttrium, and lanthanum) was suggested as a promoter to increase the dispersion and reducibility of copper and therefore it

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or phophinites [ 5 , 6 ]. However, there are few reports describing rhodium complexes with amine ligands in biphasic hydroformylation reactions which can be compared and show good performance in their catalytic activity as traditional rhodium with

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