Showing papers on "Chromium(III) oxide published in 2009"

Effect of size and morphology of chromium(III) oxide nanoparticles on their catalytic properties in deep oxidation of methane

Abstract: We have shown that the activity of catalysts based on Cr 2 O 3 in deep oxidation of methane is determined by both the sizes of the crystallites and their morphology. In the temperature range up to 450 °C, we observe the appearance of a size effect: an increase in the specific catalytic activity of the chromium oxide as its particle size decreases. Formation of chromium oxide on the surface of Al 2 O 3 increases the dispersity of the active component and increases the thermal stability of the catalyst.

Electrocatalytic Oxidation of Nitric Oxide at Carbon Paste Electrode Modified with Chromium (III) Oxide

Abstract: Chromium (III) oxide was used as a bulk mediator in carbon paste electrodes to improve the better performance of the carbon electrodes for the detection of nitric oxide in comparison with unmodified electrodes. The reaction mechanism of the electrocatalytic oxidation of NO at the modified electrode was studied using cyclic voltammetry and differential pulse voltammetry. The chemical sensor could be operated under physiological conditions (pH 7.5, 0.1 M phosphate buffer), with an operating potential of 750 mV (vs. Ag/AgCl), in hydrodynamic amperometry. The amperometric response of the sensor showed good linearity up to 200 mmol/L with a detection limit (3 σ ) of 0.69 mmol/L. The effect of the interferent nitrite was not fatal and could be eliminated by the use of the standard addition method. The new chemical sensor seems also promising to detect NO in car exhaust fumes.