Study On The Adsorption Mechanism Of TiCl₄ And O₂ On The Surface Of Rutile TiO₂(110)

With the development of our country’s economy,the demand for high-grade titanium dioxide is increasing in all sectors of society.The import volume of high-grade rutile titanium dioxide is increasing year by year.With the promotion and application in medical and environmental protection fields,the White demand will continue to increase.At present,the chlorination method is the main method for producing high-grade rutile titanium dioxide in the world.It has the advantages of good product quality,small environmental pollution,high degree of automation,and low comprehensive energy consumption.It has high application value and development in the field of titanium dioxide production.Oxidation of TiCl₄ is the core of its technology in the chlorination of titanium dioxide production processes.Years of production experience and experimental studies have shown that in the oxidation reactor,preheated TiCl₄ reacts with O₂ in the gas phase within a few milliseconds to generate a nucleation precursor of TiO₂.After reaching a certain degree of saturation,nucleation of TiO₂ begins.TiCl₄ is then formed.The adsorption and dissociation of the nucleus surface promote the growth of nuclei,and the interaction between TiCl₄ and TiCl₄ and O₂ on TiO₂（110）surface and their interaction after adsorption have not been reported.Therefore,the research on the adsorption of TiCl₄,TiCl₄ and O₂ on the nucleus surface of TiO₂ is of great significance.This research is based on the density functional theory（DFT）,using the first-principles plane wave pseudopotential method,through the CASTEP and DMol³modules of Materials Studio software to calculate the surface adsorption of TiCl₄ and TiCl₄ and O₂ on the cell surface of TiO₂（110）cell.The role of the situation,and discuss the results.The main research contents and conclusions are as follows:（1）Calculate the distance between the molecular surface and the cell surface after adsorbing TiCl₄ molecules on the surface of intact cell surface and oxygen-containing vacancy TiO₂（110）.Surface adsorption energy,charge density,differential charge density,density of states,and Mulliken charge population Wait,and discuss the results.The results show that the adsorption of TiCl₄ on the surface of TiO₂（110）is dominated by the TiCl₄ face center.The presence of oxygen vacancies on the surface promotes the adsorption of molecules.When the density of oxygen vacancies is 12.5%and 25%,the TiCl₄ molecular surface is The adsorptive adsorption distances were 2.149?and 2.065?,respectively,and the adsorption energies reached-29.7809 kJ?mol^-1 and-48.6419kJ?mol^-1,respectively.TiCl₄ showed no charge transfer when adsorbed on the complete surface,and the two oxygen vacancies surface.After adsorption,there were 0.20 eV and0.26 eV charges transferred from the TiCl₄ molecule to the cell surface,indicating that the TiCl₄ molecule was oxidized on the surface after being adsorbed on the surface.With the increase of the oxygen vacancy density,the surface oxidation of TiCl₄molecules was stronger.（2）The adsorption and dissociation processes of TiCl₄ and O₂ molecules on the surface of TiO₂（110）unit cell were calculated by Materials Studio software CASTEP and DMol³,and the adsorption of TiCl₄ and O₂ molecules on the surface of TiO₂（110）cell was calculated.Adsorption energy;state density of O₂,TiCl₄ adsorbed on each adsorption site,transition state structure of TiCl₄ and O₂ molecules on the surface of TiO₂（110）cell unit,activation energy barrier,etc.The results show that O₂ molecule is in TiO₂（110）The maximum adsorption energy of surface vertical oxygen vacancy adsorption configuration is-11.58 kJ?mol^-1.Mulliken charge population analysis shows that the surface transferred 0.12 eV charge to O₂ molecule,indicating that O₂ molecule is perpendicular to the TiO₂（110）surface.The vacancy adsorption configuration is the best adsorption configuration.