Kinetic study on preparation of substoichiometric titanium oxide via carbothermal process

摘要: Gibbs free energy was applied to analyze the carbothermal reduction process of TiO2. The phase stable diagram Ti–C–CO drawn, and it can be found that TiO2 will reduced Ti–O Magneli phase, TinO2n–1 (3 < n < 10) or Ti3O5 first then further TiC. However, in present study, Ti4O7 TiC directly when temperature lower than 800 K lg(p co/p θ ) < −1.1. route proved by results non-isothermal TG–DTA combined XRD. isothermal analysis via under 1363, 1413, 1463 1513 K performed. whole divided into two sections: Initially rate controlled an interfacial reaction, later three-dimensional diffusion. modified mathematical expressions were deduced. They fit experimental curves well. Their activation steps 241.1 323.4 kJ mol−1, respectively.