Jerimiah A. Zamora, Armando de Rezende, Reed Nieman, Neil Vaz, Andrew R. Demko, Michelle L. Pantoya, Daniel Tunega, Adelia J. A. Aquino
{"title":"Modeling adsorption reactions of ammonium perchlorate on rutile and anatase surfaces","authors":"Jerimiah A. Zamora, Armando de Rezende, Reed Nieman, Neil Vaz, Andrew R. Demko, Michelle L. Pantoya, Daniel Tunega, Adelia J. A. Aquino","doi":"10.1002/jcc.27476","DOIUrl":null,"url":null,"abstract":"<p>In this work, the effects of two TiO<sub>2</sub> polymorphs on the decomposition of ammonium perchlorate (NH<sub>4</sub>ClO<sub>4</sub>) were studied experimentally and theoretically. The interactions between AP and various surfaces of TiO<sub>2</sub> were modeled using density functional theory (DFT) calculations. Specifically, the adsorption of AP on three rutile surfaces (1 1 0), (1 0 0), and (0 0 1), as well as two anatase surfaces (1 0 1), and (0 0 1) were modeled using cluster models, along with the decomposition of adsorbed AP into small molecules. The optimized complexes of the AP molecule on TiO<sub>2</sub> surfaces were very stable, indicating strong covalent and hydrogen bonding interactions, leading to highly energetic adsorption reactions. The calculated energy of adsorption (Δ<i>E</i><sub>ads</sub>) ranged from −120.23 to −301.98 kJ/mol, with highly exergonic calculated Gibbs free energy (Δ<i>G</i><sub>ads</sub>) of reaction, and highly exothermic enthalpy of reaction (Δ<i>H</i><sub>ads</sub>). The decomposition of adsorbed AP was also found to have very negative Δ<i>E</i><sub>dec</sub> values between −199.08 and −380.73 kJ/mol. The values of Δ<i>G</i><sub>dec</sub> and Δ<i>H</i><sub>dec</sub> reveal exergonic and exothermic reactions. The adsorption of AP on TiO<sub>2</sub> surfaces anticipates the heat release of decomposition, in agreement with experimental results. The most common anatase surface, (1 0 1), was predicted to be more reactive for AP decomposition than the most stable rutile surface, (1 1 0), which was confirmed by experiments. DFT calculations show the mechanism for activation of the two TiO<sub>2</sub> polymorphs is entropy driven.</p>","PeriodicalId":188,"journal":{"name":"Journal of Computational Chemistry","volume":"45 32","pages":"2739-2748"},"PeriodicalIF":3.4000,"publicationDate":"2024-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Computational Chemistry","FirstCategoryId":"92","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/jcc.27476","RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
In this work, the effects of two TiO2 polymorphs on the decomposition of ammonium perchlorate (NH4ClO4) were studied experimentally and theoretically. The interactions between AP and various surfaces of TiO2 were modeled using density functional theory (DFT) calculations. Specifically, the adsorption of AP on three rutile surfaces (1 1 0), (1 0 0), and (0 0 1), as well as two anatase surfaces (1 0 1), and (0 0 1) were modeled using cluster models, along with the decomposition of adsorbed AP into small molecules. The optimized complexes of the AP molecule on TiO2 surfaces were very stable, indicating strong covalent and hydrogen bonding interactions, leading to highly energetic adsorption reactions. The calculated energy of adsorption (ΔEads) ranged from −120.23 to −301.98 kJ/mol, with highly exergonic calculated Gibbs free energy (ΔGads) of reaction, and highly exothermic enthalpy of reaction (ΔHads). The decomposition of adsorbed AP was also found to have very negative ΔEdec values between −199.08 and −380.73 kJ/mol. The values of ΔGdec and ΔHdec reveal exergonic and exothermic reactions. The adsorption of AP on TiO2 surfaces anticipates the heat release of decomposition, in agreement with experimental results. The most common anatase surface, (1 0 1), was predicted to be more reactive for AP decomposition than the most stable rutile surface, (1 1 0), which was confirmed by experiments. DFT calculations show the mechanism for activation of the two TiO2 polymorphs is entropy driven.
期刊介绍:
This distinguished journal publishes articles concerned with all aspects of computational chemistry: analytical, biological, inorganic, organic, physical, and materials. The Journal of Computational Chemistry presents original research, contemporary developments in theory and methodology, and state-of-the-art applications. Computational areas that are featured in the journal include ab initio and semiempirical quantum mechanics, density functional theory, molecular mechanics, molecular dynamics, statistical mechanics, cheminformatics, biomolecular structure prediction, molecular design, and bioinformatics.