Coverage-Dependent CO Adsorption Energy from First-Principles Calculations

2009 ◽  
Vol 113 (15) ◽  
pp. 6088-6092 ◽  
Author(s):  
Bin Shan ◽  
Yujun Zhao ◽  
Jangsuk Hyun ◽  
Neeti Kapur ◽  
John B. Nicholas ◽  
...  
RSC Advances ◽  
2017 ◽  
Vol 7 (69) ◽  
pp. 43521-43530 ◽  
Author(s):  
Qingxiao Zhou ◽  
Weiwei Ju ◽  
Xiangying Su ◽  
Yongliang Yong ◽  
Xiaohong Li ◽  
...  

The geometric structure, adsorption energy, electronic structure, and magnetic properties of hydrogenated graphene (graphane) with the adsorption of a HCN molecule were investigated by first-principles calculations.


2015 ◽  
Vol 816 ◽  
pp. 370-374
Author(s):  
Jun Ling Pan ◽  
Qiu Ming Peng ◽  
Jian Xin Guo ◽  
Hui Li

Grain refining is one of the most important issues in the applications of Mg alloys, which directly determines mechanical properties and deformability. Therefore the understanding of grain refining mechanism during solidification will be benefit to develop new grain refiners. Herein refining role was elucidated by the first principles calculations based on adsorption behavior of a Mg atom on the closest-packed planes of grain refiners (Zr (001), Al2Y(311) and Al4C3(102)). Taking into account different sites, the site with the maximum adsorption energy value generally corresponded to the most possible location. The adsorption energy results show that the possible refining turn follows Al4C3(102)>Zr (001)>Al2Y(311). Meanwhile, the structural optimization confirmed that the Mg atom connected with two C atoms on the top of zig-zag plane of Al4C3(102), three Zr atoms at the hcp position on Zr (001), and two Y atoms and one Al atom at the bottom of zig-zag plane of Al2Y(311). The density of states revealed that the variation of d-orbital electrons of Mg atom became apparent during adsorption process. The values of Mulliken charges were 0.898 e in Al4C3(102), 0.410 e in Zr (001) and 0.245 e in Al2Y(311), respectively. This tendency agrees well with the previous experimental results. It indicates the adsorption energy on the closest-packed planes can be regarded as a prerequisite to select new grain refiners for Mg alloys in future.


2021 ◽  
Vol 1016 ◽  
pp. 1863-1868
Author(s):  
Norio Nunomura ◽  
Jun Yamashita ◽  
Satoshi Sunada

In this study, we investigated the influence of the interaction between graphene and other materials as a basis for controlling the electronic structure of nanocarbon materials. First-principles calculations based on density functional theory (DFT) were performed on the optimized structure, adsorption energies and electronic states when copper and aluminum atoms were placed on graphene. As a result, we found that copper and aluminum are stable at the bridge and the hollow site, respectively. It was found that the adsorption energy of aluminum atom on graphene is larger than that of copper atom. It is considered that the difference in adsorption energy is caused by the difference in the dominant electron orbitals of the copper atom and the aluminum atom.


RSC Advances ◽  
2016 ◽  
Vol 6 (83) ◽  
pp. 79836-79843 ◽  
Author(s):  
Xin Wei ◽  
Chaofang Dong ◽  
Zhanghua Chen ◽  
Kui Xiao ◽  
Xiaogang Li

Using first-principles calculations based on van der Waals density functional theory, we systematically studied the co-adsorption behavior of H2O and O2 on Al(111) surfaces.


Coatings ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 763 ◽  
Author(s):  
Shuai Yang ◽  
Zhiyong Wang ◽  
Xueqiong Dai ◽  
Jianrong Xiao ◽  
Mengqiu Long ◽  
...  

Phosphorene, due to its large surface-to-volume ratio and high chemical activity, shows potential application for gas sensing. In order to explore its sensing performance, we have performed the first-principles calculations based on density functional theory (DFT) to investigate the perfect and C-doped zigzag phosphorene nanoribbons (C-ZPNRs) with a series of small gas molecules (NH3, NO, NO2, H2, O2, CO, and CO2) adsorbed. The calculated results show that NH3, CO2, O2 gas molecules have relatively larger adsorption energies than other gas molecules, indicating that phosphorene is more sensitive to these gas molecules. For C-ZPNRs configuration, the adsorption energy of NO and NO2 increase and that of other gas molecules decrease. Interestingly, the adsorption energy of hydrogen is −0.229 eV, which may be suitable for hydrogen storage. It is hoped that ZPNRs may be a good sensor for (NH3, CO2 and O2) and C-ZPNRs may be useful for H2 storage.


Crystals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 635
Author(s):  
Jinzhe Fu ◽  
Deshuai Sun ◽  
Zhaojun Chen ◽  
Jian Zhang ◽  
Hui Du

h-Fe7C3 is considered as the main active phase of medium-temperature Fe-based Fischer–Tropsch catalysts. Basic theoretical guidance for the design and preparation of Fe-based Fischer–Tropsch catalysts can be obtained by studying the adsorption and activation behavior of CO on h-Fe7C3. In this paper, the first-principles method based on density functional theory is used to study the crystal structure properties of h-Fe7C3 and the adsorption and activation CO on its low Miller index surfaces ( 1 1 ¯ 0 ) , ( 1 1 ¯ 1 ) , ( 101 ) , ( 1 1 ¯ 1 ¯ ) and ( 001 ) . It was found that the low Miller index crystal plane of h-Fe7C3 crystal has multiple equivalent crystal planes and that the maximum adsorption energy of CO at the 3F2 point of the ( 1 1 ¯ 1 ) plane is −2.50 eV, indicating that h-Fe7C3 has a better CO adsorption performance. In addition, the defects generated at the truncated position of the h-Fe7C3 crystal plane have a great impact on the adsorption energy of CO on its surface, that is, the adsorption energy of CO on Fe atoms with C vacancies is higher. The activity of CO after adsorption is greatly affected by the adsorption configuration and less affected by the adsorption energy. The higher the coordination number of Fe atoms after adsorption, the higher the CO activity. At the same time, it was found that the bonding of O and Fe atoms is conducive to the activation of CO.


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