Density functional theory calculations of the reaction pathway for methane activation on a gallium site in metal exchanged ZSM‐5

1995 ◽  
Vol 103 (6) ◽  
pp. 2102-2108 ◽  
Author(s):  
Ewa Broclawik ◽  
Hiroaki Himei ◽  
Michiyuki Yamadaya ◽  
Momoji Kubo ◽  
Akira Miyamoto ◽  
...  
Author(s):  
Huidi Yu ◽  
Yurui Xue ◽  
Lan Hui ◽  
Chao Zhang ◽  
Yan Fang ◽  
...  

Abstract Exploring new catalysts for nitrogen reduction at ambient pressures and temperatures with ultrahigh ammonia (NH3) yield and selectivity is still a giant challenge. In this work, atomic catalysts with separated Pd atoms on graphdiyne (Pd-GDY) have been synthesized and show fascinating electrocatalytic properties for nitrogen reduction. Outstandingly, the catalyst shows the highest average NH3 yield of 4.45 ± 0.30 mgNH3 mgPd−1 h−1, almost tens of orders larger than previously reported ones, and 100% reaction selectivity in neutral media. And Pd-GDY exhibits almost no decreases in the NH3 yield and Faradaic efficiency. Density functional theory calculations show that the reaction pathway prefers to perform at the (Pd, C1, C2) active area due to the strongly coupled (Pd, C1, C2) which elevates the selectivity via enhanced electron-transfer. By adjusting the p-d coupling accurately, the reduction of self-activated nitrogen is promoted by anchoring atom selection, and the side effects are minimized.


2019 ◽  
Vol 44 (1) ◽  
pp. 67-73 ◽  
Author(s):  
Ying-Ying Wang

By performing density functional theory calculations, the adsorption configurations of formic acid and possible reaction pathway for HCOOH oxidation on PtPd(111) surface are located. Results show that CO2 is preferentially formed as the main product of the catalytic oxidation of formic acid. The formation of CO on the pure Pd surface could not possibly occur during formic acid decomposition on the PtPd(111) surface owing to the high reaction barrier. Therefore, no poisoning of catalyst would occur on the PtPd(111) surface. Our results indicate that the significantly increased catalytic activity of bimetallic PtPd catalyst towards HCOOH oxidation should be attributed to the reduction in poisoning by CO.


2006 ◽  
Vol 71 (11-12) ◽  
pp. 1525-1531 ◽  
Author(s):  
Wojciech Grochala

The enthalpy of four polymorphs of CaN has been scrutinized at 0 and 100 GPa using density functional theory calculations. It is shown that structures of diamagnetic calcium diazenide (Ca2N2) are preferred over the cubic ferromagnetic polymorph (CaN) postulated before, both at 0 and 100 GPa.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Chih-Chuen Lin ◽  
Phani Motamarri ◽  
Vikram Gavini

AbstractWe present a tensor-structured algorithm for efficient large-scale density functional theory (DFT) calculations by constructing a Tucker tensor basis that is adapted to the Kohn–Sham Hamiltonian and localized in real-space. The proposed approach uses an additive separable approximation to the Kohn–Sham Hamiltonian and an L1 localization technique to generate the 1-D localized functions that constitute the Tucker tensor basis. Numerical results show that the resulting Tucker tensor basis exhibits exponential convergence in the ground-state energy with increasing Tucker rank. Further, the proposed tensor-structured algorithm demonstrated sub-quadratic scaling with system-size for both systems with and without a gap, and involving many thousands of atoms. This reduced-order scaling has also resulted in the proposed approach outperforming plane-wave DFT implementation for systems beyond 2000 electrons.


2021 ◽  
Vol 60 (8) ◽  
pp. 6016-6026
Author(s):  
Aydar Rakhmatullin ◽  
Maxim S. Molokeev ◽  
Graham King ◽  
Ilya B. Polovov ◽  
Konstantin V. Maksimtsev ◽  
...  

Author(s):  
Lijuan Meng ◽  
Jinlian Lu ◽  
Yujie Bai ◽  
Lili Liu ◽  
Tang Jingyi ◽  
...  

Understanding the fundamentals of chemical vapor deposition bilayer graphene growth is crucial for its synthesis. By employing density functional theory calculations and classical molecular dynamics simulations, we have investigated the...


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.


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