The effects of ceria and zirconium oxides additions to alumina-supported palladium catalysts on methane combustion behavior were investigated. The structure and TPR/TPO properties were studied by XRD, TPR, TPO techniq...The effects of ceria and zirconium oxides additions to alumina-supported palladium catalysts on methane combustion behavior were investigated. The structure and TPR/TPO properties were studied by XRD, TPR, TPO techniques. The results show that the addition of Ce-Zr oxides improves the thermal stability of alumina and PdO. The Pd/Ce0.2Zr0.8/Al2O3 exhibits the highest activity and thermal stability for methane combustion.展开更多
Besides the two phase transitions known in ferroelectromagnets, an additional transition was observed experimentally in Pb(Fe1/2Nb1/2)O3 and the possible mechanism was explored. The magnetic moment shows that anomalou...Besides the two phase transitions known in ferroelectromagnets, an additional transition was observed experimentally in Pb(Fe1/2Nb1/2)O3 and the possible mechanism was explored. The magnetic moment shows that anomalous increases when the temperature goes down away from the Néel temperature of 20-30 K. The existence of the hysteresis verifies the weak ferromagnetic property. This additional phase transition is considered to originate from the magnetoelectric coupling between the ferroelectric and antiferromagnetic orders in this compound. From the M?ssbauer parameter analysis, it is confirmed that the hybridization of the O 2p, Fe 3d and Nb 4d electron states makes the realization of magnetoelectric coupling possible.展开更多
文摘The effects of ceria and zirconium oxides additions to alumina-supported palladium catalysts on methane combustion behavior were investigated. The structure and TPR/TPO properties were studied by XRD, TPR, TPO techniques. The results show that the addition of Ce-Zr oxides improves the thermal stability of alumina and PdO. The Pd/Ce0.2Zr0.8/Al2O3 exhibits the highest activity and thermal stability for methane combustion.
基金Projects(50572038 10374048) supported by the National Natural Science Foundation of China
文摘Besides the two phase transitions known in ferroelectromagnets, an additional transition was observed experimentally in Pb(Fe1/2Nb1/2)O3 and the possible mechanism was explored. The magnetic moment shows that anomalous increases when the temperature goes down away from the Néel temperature of 20-30 K. The existence of the hysteresis verifies the weak ferromagnetic property. This additional phase transition is considered to originate from the magnetoelectric coupling between the ferroelectric and antiferromagnetic orders in this compound. From the M?ssbauer parameter analysis, it is confirmed that the hybridization of the O 2p, Fe 3d and Nb 4d electron states makes the realization of magnetoelectric coupling possible.
