A reactive force field molecular dynamics study on the inception mechanism of titanium tetraisopropoxide (TTIP) conversion to titanium clusters

DY Hou and MY Feng and JL Wei and Y Wang and ACT van Duin and KH Luo, CHEMICAL ENGINEERING SCIENCE, 252, 117496 (2022).

DOI: 10.1016/j.ces.2022.117496

We performed ReaxFF reactive molecular dynamics simulations to investigate the inception mechanism of TTIP precursor droplet conversion to Ti-containing clusters in 1000 K-2500 K with or without gaseous O-2 molecules. A new Ti/C/H/O ReaxFF force field has been developed. Key intermediate titanium species and the initial decomposition pathways of TTIP are identified. The effects of temperature, O-2 concentration and high-temperature residence time on the conversion of TTIP to incipient titanium clusters are investigated. Results suggest that high pyrolysis temperature does not necessarily promote the formation of incipient Ti- containing clusters, due to less stable Ti-O bonds at high temperatures. Ti2O CyHz species appear earlier than TiO2 during TTIP pyrolysis, while TiO2 forms earlier than Ti2O CyHz species and has much higher concentration with ambient O-2. Decreasing high-temperature residence time boosts the formation of Ti-containing clusters by facilitating the condensation of TiO2 vapors. The growth pattern of the incipient titanium clusters is elucidated as formation of Ti-O bond with TiOCyHz species or titanium clusters followed by continuous breakage of Ti-O or C-O bonds to release hydrocarbon moieties. (c) 2022 Elsevier Ltd. All rights reserved.

Return to Publications page