Topic
Mixed oxide
About: Mixed oxide is a research topic. Over the lifetime, 5224 publications have been published within this topic receiving 115567 citations.
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TL;DR: The results show that under specific anodization conditions self-organized porous oxide structures can be grown on the alloy surface, and represent a simple surface treatment for Ti alloys that has high potential for biomedical applications.
Abstract: The present work reports the fabrication of self-organized porous oxide-nanotube layers on the biomedical titanium alloys Ti-6Al-7Nb and Ti-6Al-4V by a simple electrochemical treatment. These two-phase alloys were anodized in 1M (NH(4))(2)SO(4) electrolytes containing 0.5 wt % of NH(4)F. The results show that under specific anodization conditions self-organized porous oxide structures can be grown on the alloy surface. SEM images revealed that the porous layers consist of arrays of single nanotubes with a diameter of 100 nm and a spacing of 150 nm. For the V-containing alloy enhanced etching of the beta phase is observed, leading to selective dissolution and an inhomogeneous pore formation. For the Nb-containing alloy an almost ideal coverage of both phases is obtained. According to XPS measurements the tubes are a mixed oxide with an almost stoichiometric oxide composition, and can be grown to thicknesses of several hundreds of nanometers. These findings represent a simple surface treatment for Ti alloys that has high potential for biomedical applications.
239 citations
TL;DR: In this article, the effect of support composition as well as metal loading on steam reforming (SR) reaction was studied in a downflow tubular fixed bed reactor at atmospheric pressure with an ethanol/water molar ratio of 1:8, over a temperature range of 400 to 650 ∘ C.
238 citations
TL;DR: A series of Mn-Ce mixed oxide catalysts with different molar ratio of Mn/Ce were prepared by the surfactant-template (ST) method and conventional co-precipitation (CP) method for the selective catalytic reduction of NOx with ammonia (NH3-SCR) at low temperatures as mentioned in this paper.
236 citations
TL;DR: In this paper, NiO dispersion and part of its incorporation into the mixed oxide lattice has been shown to increase the activity and stability of NiO catalysts in carbon dioxide methanation.
Abstract: Ni–Ce0.72Zr0.28O2 catalysts containing up to 15 wt% Ni were prepared, characterized and their catalytic activity was investigated in carbon dioxide methanation. The impact of the pre-treatment and the gas hourly space velocity were also studied. NiO dispersion and part of its incorporation into the mixed oxide lattice obviously increased the activity and stability of the catalysts. Very high CO2 conversions were achieved at 350 and 400 °C, together with extremely high selectivity to methane (>98%) for all catalysts. Finally, high stability on stream toward deactivation was observed up to 150 h at 350 °C. 10 wt%Ni–Ce0.72Zr0.28O2 was found to be the optimal catalyst.
234 citations
TL;DR: In this article, a series of manganese-niobium mixed oxide (Mn-Nb) catalysts were prepared by homogeneous precipitation method and tested for low temperature selective catalytic reduction of NOx with NH3 (NH3-SCR).
231 citations