Four photo-catalysts of the general formula [Ir(CO6/ppy)2(L)]Cl where CO6=coumarin 6 ( Ir1 – Ir3 ), ppy=2-phenylpyridine ( Ir4 ), L=4′-(3,5-di-tert-butylphenyl)-2,2′ : 6′,2′′-terpyridine ( Ir1 ), 4′-(3,5-bis(trifluoromethyl)phenyl)-2,2′ : 6′,2′′-terpyridine ( Ir2 and Ir4 ), and 4-([2,2′ : 6′,2′′-terpyridin]-4′-yl)-N,N-dimethylaniline ( Ir3 ) were synthesized and characterized. These photostable photo-catalysts ( Ir1 – Ir3 ) showed strong visible light absorption between 400–550 nm. Upon light irradiation (465 and 525 nm), Ir1 – Ir3 generated singlet oxygen and induced rapidly photo-catalytic oxidation of cellular coenzymes NAD(P)H. Ir1 – Ir3 showed time-dependent cellular uptake with excellent intracellular retention efficiency. Upon green light irradiation (525 nm), Ir2 provided a much higher photo-index (PI=793) than the clinically used photosensitizer, 5-aminolevulinicacid (5-ALA, PI>30) against HeLa cancer cells. The observed necro-apoptotic anticancer activity of Ir2 was due to the Ir2 triggered photo-induced intracellular redox imbalance (by NAD(P)H oxidation and ROS generation) and change in the mitochondrial membrane potential. Remarkably, Ir2 showed in vivo photo-induced catalytic anticancer activity in mouse models. 相似文献
FeOx, TiO2, and Fe–Ti–Ox catalysts were synthesized and used in the catalytic hydrolysis of hydrogen cyanide (HCN). Nearly 100% HCN conversion was achieved at 250 °C over the Fe–Ti–Ox catalyst. TiO2 rutile was detected over TiO2, but not over Fe–Ti–Ox, which suggested that the interaction between Fe and Ti species could inhibit the TiO2 phase transition. Furthermore, the interaction between Fe and Ti species over Fe–Ti–Ox could promote the selectivity of NH3 and CO. The mechanism of hydrolysis of HCN over FeOx, TiO2, and Fe–Ti–Ox can be given as follows: HCN + H2O → methanamide → ammonium formate → formic acid → H2O + CO. 相似文献
A series of Ce-Fe-Ox catalysts prepared by the different calcination temperatures (marked as CF-X, where X represented calcination temperature) were used to the selectivity catalytic reduction of NOx by NH3. The results explained the relationship between calcination temperature and the sulfate species over Ce-Fe-Ox, and then investigated the surface acidity and catalytic performance. The large amounts of sulfate species were formed over CF-450 and CF-550 while it was decomposed with further the increasing of calcination temperature, which resulted in the loss of surface acidity, causing a decrease in the catalytic activity over Ce-Fe-Ox. Thereby, the CF-450 catalyst showed the best catalytic activity and over 90% NOx conversion was obtained at 244–450 °C. Besides, the favored pore structure, more Fe3+ active species, higher Ce3+ concentration and the abundance of chemical adsorbed oxygen species, as well as the surface acid sites, would together contribute to the excellent catalytic activity of CF-450 catalyst. 相似文献
6–8 mass% Y2O3 stabilized ZrO2 (6–8YSZ) thermal barrier coatings (TBCs) are widely applied to protect the hot ends of gas turbines in large navy ships. In this work, the 8YSZ TBCs were prepared by air plasma spraying technique, and their microstructure and phase composition were investigated. The hot corrosion mechanism of YSZ TBCs in molten salts consisting of 80% Na2SO4?+?20% NaCl at 900 °C was comprehensively analyzed. The results showed that the corrosion product Y2(SO4)3 was formed due to the reaction between Na2SO4 media and the stabilizer Y2O3. As the result of the depletion of Y2O3 phase, the transformation from the tetragonal phase to monoclinic phase of ZrO2 could not been totally inhibited, which consequently induced the 4–6 vol.% expansion and more cracks of YSZ TBCs. Meanwhile, the cracks could work as transfer paths for oxygen and molten salts. The kinetic analysis on hot corrosion also showed that more reaction products (from 2 to 8.1 mg cm?1) were generated from 20 to 60 h due to more cracks generated by molten salts and oxygen infiltrating. More thermal grown oxides generated between ceramic layer, bonding layer and substrate, and the volume expansion caused by phase transition, increased the stresses in the coatings. Consequently, the peeling-off failure of 8YSZ TBCs could happen.
Research on Chemical Intermediates - The effect of different pH values (8, 9, 10 and 11) on the catalytic activity over CeSiW catalysts was investigated for the selective catalytic reduction of NO... 相似文献
A Pd-catalyzed haloallylation of alkynes with allyl alcohols in ionic liquids has been reported. Both chloroallylation and bromoallylation can be easily carried out with high selectivity. A variety of 1,4-dienes were formed in moderate to excellent yields. The reaction system of the Pd catalyst as well as the ionic liquid can be recycled for several times. And the ionic liquid acts as not only a solvent in the reaction, but also provides the excess halide ions to control Z/E selectivity and acts as a ligand inhibit the β-hydride elimination. 相似文献
A series of precipitants and commercial surfactants (soft templates) were employed to synthesize mesoporous/nano CeO2 by a hydrothermal method. As-prepared CeO2 was impregnated with palladium and employed for low-temperature catalytic oxidation of CO. It was found that both soft templates and precipitants had significant effects on the morphology, particle size, crystallinity, and porous structure of the CeO2, having a significant effect on the surface palladium abundance, molar ratios of surface species, and catalytic activity of the final impregnated Pd/CeO2. Using ammonia as precipitant could facilitate increased surface palladium abundance and surface molar ratios of PdO/PdSMSI, Ce3+/(Ce3+ + Ce4+), and Osurface/Olattice. The catalytic activity of the final Pd/CeO2 catalysts could be enhanced as well. The optimal P123-assisted ammonia-precipitated Pd/CeO2 catalyst exhibited over 99% catalytic conversion of CO at 50 °C. 相似文献
The effect of Mg and C contents on TC in MgCN3, and structure and superconductivity of MgCNi3-xCox were studied. It is found that the excess of Mg and C in initial material mixture is favorable to improvement inTc and helps to obtain single-phase samples. For preparing MgCNi3 superconductor, the optimum composition of starting materials is MgC1.45Ni3 with excess of Mg (20 wt.%) of the stoichiometric composition. In gCNi3-xCox system, a continuous solid solution is formed, lattice parameter decreases slightly andTc decreases obviously with increasingx. A suppression of superconductivity is observed due to the substitution of Co (Mn) for Ni. The suppression effect is smaller
for the substitution of Co than that of Mn 相似文献
The effect of Mg and C contents on TC in MgCN3, and structure and superconductivity of MgCNi3-xCox were studied. It is found that the excess of Mg and C in initial material mixture is favorable to improvement inTc and helps to obtain single-phase samples. For preparing MgCNi3 superconductor, the optimum composition of starting materials is MgC1.45Ni3 with excess of Mg (20 wt.%) of the stoichiometric composition. In gCNi3-xCox system, a continuous solid solution is formed, lattice parameter decreases slightly andTc decreases obviously with increasingx. A suppression of superconductivity is observed due to the substitution of Co (Mn) for Ni. The suppression effect is smaller for the substitution of Co than that of Mn 相似文献