Methane adsorption properties of N-doped graphdiyne: a first-principles study

• Published in: Structural chemistry Vol. 32; no. 4; pp. 1517 - 1527
• Main Authors: Xu, Wenhui, Chen, Yuhong, Zhao, Yingjie, Zhang, Meiling, Tian, Ranran, Zhang, Cairong
• Format: Journal Article
• Language: English
• Published: New York Springer US 2021; Springer Nature B.V
• Subjects: Acetylene; Adsorption; Chemistry; Chemistry and Materials Science; Computer Applications in Chemistry; First principles; Methane; Original Research; Physical Chemistry; Substrates; Theoretical and Computational Chemistry; Van der Waals forces; N-doped; Methane; Adsorption properties; Graphdiyne; A first-principles
• ISSN: 1040-0400; 1572-9001
• DOI: 10.1007/s11224-020-01716-4

N-doped graphdiyne (N-graphdiyne) is a new kind of alkynyl carbon material whose structure resembles graphdiyne. This study describes the Mn-modified N-graphdiyne (Mn-N-graphdiyne) system on methane (CH
4
) adsorption properties based on first principles. We found that the modifications of the Mn atom could significantly improve the adsorption of CH
4
by N-graphdiyne. Two Mn atoms can adsorb 36 CH
4
molecules upon double-sided modification, with average adsorption capacity and storage capacities of approximately − 0.158 eV and 0.585 g g
−1
, respectively. The adsorption of the first CH
4
molecule by the Mn-N-graphdiyne system, which is mainly affected by the Mn atoms, involves a strong Coulomb interaction with Mn accompanied by the highest adsorption energy. Subsequently, an increase in the distance between CH
4
molecules and Mn atoms increases leads to a weakened Coulomb interaction. The adsorption of CH
4
molecules is then mainly affected by the van der Waals force between the substrate N-graphdiyne, and the adsorption energy decreases. The N-graphdiyne system has a larger acetylene chain macroporous position than GDY owing to the doping of N atoms, which provides sufficient adsorption space and adsorption sites for CH
4
.