Temperature-Programmed and X-Ray Diffractometry Studies of WO<sub>3</sub> Reduction by Carbon Monoxide

Abstract

Tungsten (VI) oxide (WO3) reduction by carbon monoxide were examined using temperature-programmed reduction (TPR) and X-ray powder diffractometry (XRD) studies. Results show that WO3 start to reduce at 20% (CO in N2) at temperature 900 °C and the intermediate phases WO2.9 and WO2.83 were observed. The WO3 was reduced and transformed the completely to the WO2.72. As comparison, reduction by using 10% (H2 in N2), WO3 was reduced completely toWO2. The WO3 is a stable oxide because the reduction agent used to promote the reduction was not sufficient enough to reduce to zero metal tungsten.