scholarly journals Study on the adsorption selection of CH$$_4$$ on CuO (110) versus (111) surfaces: a density functional theory study

2021 ◽  
Vol 3 (4) ◽  
Author(s):  
Long Lin ◽  
Linwei Yao ◽  
Shaofei Li ◽  
Zhengguang Shi ◽  
Kun Xie ◽  
...  

AbstractFinding the active sites of suitable metal oxides is a key prerequisite for detecting CH$$_4$$ 4 . The purpose of the paper is to investigate the adsorption of CH$$_4$$ 4 on intrinsic and oxygen-vacancies CuO (111) and (110) surfaces using density functional theory calculations. The results show that CH$$_4$$ 4 has a strong adsorption energy of −0.370 to 0.391 eV at all site on the CuO (110) surface. The adsorption capacity of CH$$_4$$ 4 on CuO (111) surface is weak, ranging from −0.156 to −0.325 eV. In the surface containing oxygen vacancies, the adsorption capacity of CuO surface to CH$$_4$$ 4 is significantly stronger than that of intrinsic CuO surface. The results indicate that CuO (110) has strong adsorption and charge transfer capacity for CH$$_4$$ 4 , which may provide experimental guidance.

Author(s):  
Pei Zhao ◽  
Bundet Boekfa ◽  
Ken-ichi Shimizu ◽  
Masaru Ogura ◽  
Masahiro Ehara

Density functional theory calculations have been applied to study the selectivity caused by the cage size during the selective catalytic reduction of NO by NH3 over the Cu-exchanged zeolites with cha, gme, and aft cages.


Author(s):  
N. K. Das ◽  
K. Rigby ◽  
N. H. de Leeuw

Density functional theory calculations have been used to study the incorporation of helium in perfect and defect-containing palladium tritides, where we have calculated the energetics of incorporation and the migration behaviour. Helium atoms preferably occupy the octahedral interstitial and substitutional sites in the perfect and Pd vacancy-containing tritides, respectively. The energetics reveal that helium clusters can form in the lattice, which displace the Pd metal atoms. The defective lattice shows less expansion compared with the perfect lattice, which can accommodate the helium less easily. The path from octahedral–tetrahedral–octahedral sites is the lowest energy pathway for helium diffusion, and the energetics indicate that the helium generated from tritium decay can accumulate in or near the octahedral sites. Density of states analyses shows the hybridization between palladium d and tritium s orbitals and repulsion between palladium d and helium s orbitals, which can distort the lattice as a result of generating localized stress.


2002 ◽  
Vol 716 ◽  
Author(s):  
Maciej Gutowski ◽  
John E. Jaffe ◽  
Chun-Li Liu ◽  
Matt Stoker ◽  
Anatoli Korkin

AbstractIt is known that the chemistries of hafnium and zirconium are more nearly identical than for any other two congeneric elements. Thus, both zirconia and hafnia, with the dielectric constant K > 20, have emerged as potential replacements for silica (K = 3.9) as a gate dielectric. We report an important difference between the zirconia/Si and hafnia/Si interfaces based on density functional theory calculations with the Perdew-Wang 91 exchange-correlation functional on the oxides, silicides, and silicates of Zr and Hf. The zirconia/Si interface has been found to be unstable with respect to formation of silicides whereas the hafnia/Si interface is stable. The difference between the two interfaces results from the fact that HfO2 is more stable than ZrO2 (i.e. has a larger heat of formation from its constituent elements) by more than 53 kJ/mol. The hafnium silicides, on the other hand, are less stable than zirconium silicides by ca. 20 kJ/mol.


2013 ◽  
Vol 1495 ◽  
Author(s):  
Massimo Malagoli ◽  
M.L. Liu ◽  
Hyeon Cheol Park ◽  
Angelo Bongiorno

ABSTRACTDensity functional theory calculations are used to study the equilibrium energetics of protons on the surface and in the bulk of Y-doped BaZrO3. It is shown that protonic species in direct contact with Y dopants have energies lower than in perfect BaZrO3 by up to 0.4 eV. This energetic stabilization is achieved when the protonic species is in direct contact with two Y dopants. On the (001) surface of BaZrO3, protonic species are found to be energetically more stable than in the bulk by 1.1 eV and 1.6 eV on the BaO and ZrO2 surface terminations, respectively. At these terminations, the energy of protons recover the bulk value after penetrating three surface layers, and the energy cost associated with bulk incorporation is larger than 1 eV.


RSC Advances ◽  
2020 ◽  
Vol 10 (66) ◽  
pp. 39988-39994
Author(s):  
Zongzi Jin ◽  
Ranran Peng ◽  
Yunpeng Xia ◽  
Zhenbin Wang ◽  
Wei Liu

Density functional theory calculations are employed to investigate the formation and conducting behaviors of oxygen vacancies and proton defects in Ruddlesden–Popper oxide SrEu2Fe2O7.


2017 ◽  
Vol 41 (21) ◽  
pp. 12569-12580 ◽  
Author(s):  
Amirali Abbasi ◽  
Jaber Jahanbin Sardroodi

The adsorption behaviors of SOx molecules on pristine and N-doped ZnO nanoparticles were investigated using density functional theory calculations (DFT).


Author(s):  
Xin-Chen Zhu ◽  
Wei Zhang ◽  
Qian Xia ◽  
Anfu Hu ◽  
Jian Jiang ◽  
...  

To study the effect of coordination field on catalytic property is critical for rational design of outstanding electrocatalyst for H2O2 synthesis. Herein, via density functional theory calculations, we built an...


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