A novel synthesis process for MoO ₂ and Mo ₂ C particles

This study presents a novel process for the synthesis of MoO 2 and Mo 2 C particles. It consisted of waste polyethylene (PE) pyrolysis and MoO 3 reaction with pyrolytic gas in a furnace with two‐independently controlled zones. The gaseous species such as H 2 and CH 4 were in situ generated from the waste during heating to the temperatures ranging from 670 to 800 K. The resultant pyrolytic gas was carried to the MoO 3 powder bed by Ar flow to obtain MoO 2 at 900 K. Mo 2 C was synthesized in the temperature range 1000–1300 K by the reaction of pre‐reduced MoO 2 with the pyrolytic gas. Mo 4 O 11 , MoO 2 , and Mo 2 C phases sequentially formed during the reduction and carburization of the MoO 3 powder. Mo 4 O 11 phase played an intermediate role in the reduction, as predicted by the thermodynamics. MoO 2 and Mo 2 C phases were obtained at PE/oxide reactant ratios higher than those predicted. The discrepancy was discussed in terms of essential characteristics of the thermodynamics and the experiments. Mo 2 C powders consisted of fine platelet‐shaped crystals similar to those of MoO 2 . Mo 2 C crystallite size decreased, whereas microstrain increased as the carburization temperature decreased. This study demonstrates that waste PE can be recycled as alternative H 2 and C resources in reduction/carburization processes.