Low-temperature oxidation of methane mediated by Al-doped ZnO cluster and nanowire: a first-principles investigation

• Published in: Journal of molecular modeling 2024-11, Vol.30 (11), p.370-370, Article 370
• Main Author: Esrafili, Mehdi D.
• Format: Article
• Language: English
• Subjects: activation energy; adsorption; aluminum; Catalytic oxidation; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Clusters; Computer Appl. in Life Sciences; Computer Applications in Chemistry; Decomposition reactions; Density functional theory; Electronic structure; energy; First principles; formaldehyde; geometry; Hydrogen bonds; Low temperature; Methane; methanol; Molecular Medicine; Nanowires; Nitrous oxide; Original Paper; Oxidation; Oxidizing agents; Pseudopotentials; Relativistic effects; species; Theoretical and Computational Chemistry; Zinc oxide
• ISSN: 1610-2940; 0948-5023; 0948-5023
• DOI: 10.1007/s00894-024-06168-9

Context First-principles calculations are performed to investigate the catalytic oxidation of methane by using N 2 O as an oxidizing agent over aluminum (Al)-doped Zn 12 O 12 cluster and (Zn 12 O 12 ) 2 nanowire. The impact of Al impurity on the geometry, electronic structure, and surface reactivity of Zn 12 O 12 and (Zn 12 O 12 ) 2 is thoroughly studied. Our study demonstrates that Al-doped ZnO systems have a better adsorption ability than the corresponding pristine counterparts. It is found that N 2 O molecule is initially decomposed on the Al site to provide the N 2 molecule, and an Al–O intermediate which is an active species for the CH 4 oxidation. The conversion of CH 4 into CH 3 OH over AlZn 11 O 12 and (AlZn 11 O 12 ) 2 requires an activation energy of 0.45 and 0.29 eV, respectively, indicating it can be easily performed at normal temperatures. Besides, the overoxidation of methanol into formaldehyde cannot take place over the AlZn 11 O 12 and (AlZn 11 O 12 ) 2 , due to the high energy barrier needed to dissociate C–H bond of the CH 3 O intermediate. Method Dispersion-corrected density functional theory calculations were performed through GGA-PBE exchange–correlation functional combined with a numerical double-ζ plus polarization (DNP) basis set as implemented in DMol 3 . To include the relativistic effects of core electrons of Zn atoms, DFT-semicore pseudopotentials were adopted. The DFT + D scheme proposed by Grimme was used to involve weak dispersion interactions within the DFT calculations. The reaction energy paths were generated by the minimum energy path calculations using the NEB method.