Authors:Václav Čuba, Tereza Pavelková, and Viliam Múčka
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.
metalloporphyrins, could remarkably improve the catalyticactivity 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
Authors:Shengwen Chen, Changwen Ma, Minmin Qin, Haifeng Yang, Hongyong Xie, and Jie Guan
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 catalyticactivity in the epoxidation of cyclohexene was
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 catalyticactivities of Ru/AC catalyst for bromate reduction were systematically
Authors:Zongxue Yu, Yuxi Sun, Wenxian Wei, Lude Lu, and Xin Wang
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.
Authors:N. N. Das, P. K. Satapathy, S. C. Dash, and P. Mohanty
Schiff base complexes, Mn(III), Co(II), and Cr(III) complexes have gained prominence because of their catalyticactivities for a variety of oxidative organic transformations in the presence of hydrogen peroxide or organic peroxides both in homogeneous and
Authors:Jelliarko Palgunadi, Indri Yati, and Kwang Jung
expected to improve the catalyticactivity 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
Authors:Yuraima Fonseca, Bernardo Fontal, Marisela Reyes, Trino Suárez, Fernando Bellandi, Juan C. Diaz, and Pedro Cancines
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 catalyticactivity as traditional rhodium with