On the Reduction of MoO3 to MoO2 : A Path to Control the Particle Size and Morphology

Chemistry. 2021 Dec 23;27(72):18141-18149. doi: 10.1002/chem.202103417. Epub 2021 Nov 16.

Abstract

During the reduction of molybdenum trioxide (MoO3 ) to metallic molybdenum, the first reduction step yielding molybdenum dioxide as an intermediary product is of crucial importance. In this study, we examined the impact of the parameters reduction temperature, water influx, and potassium content on the hydrogen reduction of this first reaction step. Beginning from the same starting material, the chemical vapor transport mechanism was utilized to yield the phase pure MoO2 . Analyses including powder X-ray diffraction, inductively coupled plasma-mass spectrometry, scanning electron microscopy, and high performance optical microscopy were performed on the product phases. Modulations of the specific surface areas of molybdenum dioxide ranging from 2.28 to 0.41 m2 /g were possible. Furthermore, a distinct shift from small plate-like grains to cuboid-like forms was achieved.

Keywords: hydrogen reduction; molybdenum oxide; potassium; powder diffraction; scanning electron microscopy.