Study on hydrogen reduction of Mo4O11

Reduction of prepared Mo4O11 particles by hydrogen was investigated on lab scale in the temperature range of 791 to 909 K using a thermo-gravimetric analyzer. It was found that large Mo4O11 particles were first reduced to small plate-shaped MoO2 subgrains, then to metal Mo. The shape of final product Mo subgrains was kept the same as that of MoO2 ones. The product Mo obtained at high temperature presented many cracks and pores, and was a little larger than that prepared at low temperature. From Mo4O11 to MoO2, the reduction obeyed nucleation and growth mechanism at the low temperature and chemical reaction mechanism at the high temperature, while from MoO2 to Mo, the reduction controlling step was chemical reaction at the reaction interface. Based on kinetic analyses, the corresponding kinetic parameters were obtained.