Mixed oxide

About: Mixed oxide is a research topic. Over the lifetime, 5224 publications have been published within this topic receiving 115567 citations.

Magnetically Separable Gold Catalyst for the Aerobic Oxidation of Amines

Abstract: A magnetically separable, recyclable gold catalyst consisting of gold nanoparticles supported on intimately mixed superparamagnetic ceria/iron oxide has been prepared by simple addition of the preformed mixed oxide support and the gold precursor, Au(OAc)3, to the reaction mixture of the aerobic oxidation of amines. The catalyst was characterized by means of X-ray diffraction (XRD), N2 adsorption, superconducting quantum-interference device (SQUID) measurements, time-of-flight secondary ion mass spectrometry (TOF-SIMS), scanning transmission electron microscopy (STEM), and scanning electron microscopy with an energy-dispersive X-ray spectrometer (SEM-EDAX). Catalytic tests with various amines showed high selectivity to the corresponding imines (87–100 %), and good separation efficiency and recyclability of the catalyst.

Partial oxidation of methane to synthesis gas over supported Ni catalysts prepared from Ni-Ca/Al-layered double hydroxide

Abstract: The Ni-supported catalysts have been prepared in situ by the solid phase crystallization (spc) method starting from layered double hydroxides (LDHs) as the precursor and tested for the partial oxidation of methane to synthesis gas. The spc-Ni/M–Al (M: Mg, Ca and Sr) catalysts were prepared from Ni–M/Al-LDHs as the precursors, and the activities were studied in relation to the structure of the catalysts and compared with those prepared by the impregnation method. Among the catalysts tested, spc-Ni/Ca–Al was easily reduced to form active Ni metal particles during the reaction and showed the highest activity and selectivity to synthesis gas production as well as the highest sustainability against coke formation on the catalyst. The high activity and the high sustainability against coke formation of spc-Ni/Ca–Al may be due to the stable and highly dispersed Ni metal particles in addition to the basic property of Ca–Al mixed oxide as the support.

Copper Promoted Cobalt and Nickel Catalysts Supported on Ceria−Alumina Mixed Oxide: Structural Characterization and CO Oxidation Activity

Abstract: Catalytic activity of CoO, NiO, CuO−CoO, and CuO−NiO nanocrystalline mono- and bimetallic catalysts over a thermally stable and high surface area ceria−alumina mixed oxide support was evaluated for oxidation of carbon monoxide at normal atmospheric pressure and lower temperatures. The content of Co or Ni in the respective monometallic catalysts was 10 wt % and the Cu-promoted samples contained 5 wt % each. These catalysts were prepared by a wet impregnation procedure and the CeO2−Al2O3 support was obtained by a deposition precipitation method. The synthesized catalysts were characterized by BET surface area, X-ray diffraction (XRD), energy dispersive X-ray microanalysis (EDX), temperature-programmed reduction (TPR), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) techniques. XRD patterns of 773 K calcined samples revealed the presence of metal oxide phases, namely, CeO2, CuO, NiO, and Co3O4 in the respective catalysts. However, after calcination at 1073 K, the XRD lines ...