Production of Toluene by Decomposition of 2-Hydroxy-6-methylbenzaldehyde: A DFT Study

Adsorption and Gas-Sensing Properties of Agn (n = 1-4) Cluster Doped GeSe for CH4 and CO Gases in Oil-Immersed Transformer

The adsorption mechanism of CO and CH₄ on GeSe, modified with the most stable 1-4 Ag-atom clusters, is studied with the help of density functional theory. Adsorption distance, adsorption energy, total density of states (TDOS), projected density of states (PDOS), and molecular orbital theory were all used to analyze the results. CO was found to chemisorb exothermically on GeSe, independent of Ag cluster size, with Ag₄-GeSe representing the optimum choice for CO gas sensors. CH₄, in contrast, was found to chemisorb on Ag-GeSe and Ag₂-GeSe and to physisorb on Ag₃-GeSe and Ag₄-GeSe. Here, Ag GeSe was found to be the optimum choice for CH₄ gas sensors. Overall, our calculations suggest that GeSe modified by Ag clusters of different sizes could be used to advantage to detect CO and CH₄ gas in ambient air.

Adsorption of Greenhouse Decomposition Products on Ag2O-SnS2 and CuO-SnS2 Surfaces

In this paper, based on density functional theory, the adsorption mechanism and gas sensitivity of Ag₂O/CuO-modified SnS₂ were analyzed. The results were analyzed according to the adsorption energy, total density of states, partial density of states, and frontier molecular orbital theory. The results show that the adsorption of all gas molecules is exothermic. NH₃, Cl₂, and C₂H₂ gases are chemisorbed on the modified SnS₂ surfaces. After gas adsorption, the energy gap of the base changes by more than 10%, which fully shows that the conductivity changes greatly after gas adsorption, which can be reflected in the macroscopic resistance change. Ag₂O-SnS₂ is suitable as a gas sensor for NH₃ gas sensors in terms of moderate adsorption distance, large adsorption energy, charge transfer, and frontier molecular orbital theory, while CuO-SnS₂ is more suitable as a C₂H₂ gas sensor.