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Molybdenum hemicarbide (Mo2C) can be widely used in the fields of steel, metal ceramics, and catalyst of hydrogen-involved reactions. This work reported a new and simple method for preparing molybdenum hemicarbide by reducing and carbonizing MoO2 with methanol, and both thermodynamic and experimental studies were carried out. Based on the results, the reduction and carbonization routes are obtained: MoO2 was reduced and carburized directly to Mo2C in one step at lower temperatures, and first reduced to metallic Mo and then carburized to Mo2C at higher temperatures. The reduction mechanisms at low and high temperatures were proposed as well: The pseudomorphic transformation mechanism dominated the reaction at low temperatures, but at high temperatures, the reaction obeyed the chemical vapor transport mechanism. [ABSTRACT FROM AUTHOR]

Titanium oxycarbide can be used as a soluble anode to produce sponge titanium in USTB or MER molten salt electrolysis process. However, the key factor of these two processes is to prepare oxycarbide with appropriate C/O ratio and at a low cost as well. This work reported a simple method of preparing titanium oxycarbide from TiO 2 in C-H 2 system. Based on the prediction of thermodynamic calculations, titanium oxycarbide was prepared successfully at 1400 °C with the molar ratio of TiO 2 to carbon exceeding 1:2, and the ideal electrolytic anode (TiC 0.5 O 0.5) was produced at 1400 °C (with a ratio of 1:3 of TiO 2 to carbon). Number of parameters (carbon content, temperature, sample's mass, additive (Fe element), and with ball milling treatment) were considered and discussed in the current study. Furthermore, this method can reduce not only the reaction temperature and time, but also the emission of carbon dioxide. • Titanium Oxycarbide with controllable C/O ratio was produced by considering number of parameters in TiO 2 -C-H 2 System. • The ideal electrolytic anode (TiC 0.5 O 0.5) can be produced when the ratio of TiO 2 to carbon is 1:3 at 1400 °C. • The reaction temperature, the usage and emission of carbon were reduced by introducing clean energy (H 2). • The reaction mechanism was discussed as well. [ABSTRACT FROM AUTHOR]

Tungsten carbides, which can be widely used as cutting and drilling tools, chemical catalysts and aerospace coatings, have attracted widespread attentions. The present work reported a simple method to prepare tungsten carbides by using WO 2 as the raw materials and CO as the reduction and carbonization agent. It was found that at lower and moderate temperatures, all the final product was WC, while at higher temperatures, the final products were W 2 C or W. The reduction and carbonization mechanism was also studied theoretically and experimentally. WO 2 was reduced and carburized to WC in one step at lower temperatures; WO 2 was first reduced and carburized to W 2 C and then to WC at moderate temperatures; while at higher temperatures, WO 2 was first reduced to metallic W and then carbonized to WC or W 2 C, but with the temperature increasing, the carbonization became difficult and required much higher CO content. [ABSTRACT FROM AUTHOR]