Hydrogen reduction: A novel method of synthesizing ultra-fine chromic oxide powder

Abstract

The ultra-fine chromic oxide powder was prepared by a novel gas-solid reduction reaction. Na₂CrO₄ was firstly reduced with hydrogen at 400–600 °C. The obtained reduction products, mainly the mixture of NaCrO₂ and sodium hydroxide (NaOH), were converted into chromic oxide through hydrolysis followed by calcination. The obtained chromic oxide product was characterized by powder X-ray diffraction (XRD) and SEM. The results show that the hydrolysis process of sodium chromite is the key step and lower reduction temperature helps intensify the hydrolysis process.

Keywords

chromic oxide / gas-solid reduction / ultra-fine powder

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