Exploring effects of reactant’s chemical environments on adsorption and reaction mechanism by global optimization and IR spectrum calculation, using NO oxidation as a case

• Published in: Applied surface science 2024-12, Vol.677, p.160996, Article 160996
• Main Authors: Li, Chunrong, Zhang, Jiafei, Guan, Lifang, Hao, Qinglan, Zhang, Weiyi, Zhou, Yuwei, Teng, Botao, Wen, Xiaodong
• Format: Article
• Language: English
• Subjects: Density functional theory; Electronic structure analysis; Infrared spectrum calculation; Reaction pathway; Surface species
• ISSN: 0169-4332
• DOI: 10.1016/j.apsusc.2024.160996

Combining global optimization of surface species at different chemical environments with electronic structure analysis and IR spectrum calculation including frequency and intensity, the stable arrangement of reactants and its transformation, as well as oxidation pathway were revealed at the molecular level. [Display omitted] •Global optimization and IR spectrum calculation were used to identify surface species.•Effect of reactant’s chemical environment on NO adsorption and oxidation was studied.•Arrangement and transformation of NO and NO2 at different environments were revealed.•Oxidation pathway was elucidated by global optimization, TS and IR calculation. Reactant’s chemical environments derived from the type and concentration of surface species on heterogeneous catalysts do great effects on the structures of reactants and reaction pathway. Unraveling the arrangement of surface species and reaction mechanism at different reactant’s chemical environments in theory remains a substantial challenge due to the difficulty in obtaining the global stable configuration of surface species on catalysts and the lack of other theoretical evidences for the identification of surface species and reaction pathway. To solve this problem, a protocol combining the global optimization of surface species at different chemical environments with electronic structure analysis and IR spectrum calculation including frequency and intensity was proposed to unravel the arrangement of surface species and their reaction pathway in this work. Using NO adsorption and oxidation on Pt(111) and O-covered Pt(111) as a case, their stable structures were obtained by the global optimization; then the origins of the structural transformation of NO and NO2 at different environments were elucidated by electronic structure analysis; then the structures and reaction pathway were confirmed by comparing the experimental and calculated IR spectra of NO and NO2 with frequency and intensity. Utilizing this protocol, the stable structures of NO and its transformation, as well as oxidation pathway were revealed under varying chemical environments at the molecular level. It provides solid supports for identifying the stable arrangement of surface species, their transformation and reaction pathway, and can be easily extended to heterogeneous catalysis.