2024 AIChE Annual Meeting
Kinetics Studies of Anatase-Rutile Transition
Titanium dioxide (TiO2) is a material that has drawn attention for its chemical stability and versatile catalytic properties. The transitions among three crystalline structures, namely anatase, rutile, and brookite, are important for building and understanding the structure-property relationship of TiO2. Meanwhile, chemical kinetics studies provide an efficient and powerful methodology to identify mechanisms behind chemical reactions. Differential thermal analysis (DTA) was employed to study the underlying kinetics of the TiO2 phase transition. Various heating rates (2.5-20°C/min) were investigated and, using the Ozawa-Flynn-Wall (OFW) method, values of the activation energy (Ea) and pre-exponential factor (A) were determined. Lastly, the DTA data was fitted to a group of common kinetic models. My results suggested the anatase-rutile transition is an exothermic process and, importantly, the transition follows a nucleation and nuclei growth mechanism. This work provides the groundwork for understanding the structure transformation of TiO2, leading to insight on its catalytic performances.