N–H bond activation in ammonia by TM-SSZ-13 (Fe, Co, Ni and Cu) zeolites: a first-principles calculation

2019 ◽  
Vol 21 (3) ◽  
pp. 1506-1513 ◽  
Author(s):  
Linxia Wang ◽  
Haijun Chen ◽  
Weichao Wang

For Cu-SSZ-13, the lowest unoccupancy of b1g (dx2−y2) promotes the NH3 activation with an energy barrier of 1.26 eV.

2018 ◽  
Author(s):  
Muhammad Haris Mahyuddin

An interesting prospective pseudomorphic overlayer on bcc surface material as implemented in Pd pseudomorphic overlayer on V(110) surface has been introduced in the frame work of first-principles calculation. Adsorption and decomposition of H2S molecule were calculated on this overlayer structure. In comparison, we also calculated them on their bare V(110) and Pd(111) surfaces. It was found that Pseudomorphic overlayer surface structure weakened the adsorption energy of H2S, SH, S and H compared to its bare Pd(111) and V(110) surfaces. Furthermore, Pd/V(110) surface was found to have higher activation energy barrier for H2S and SH dissociation than its bare Pd(111) and V(110) do. Pd/V(110) surface is predicted to be a promising catalyst membrane used in gas-shift reactor technology because besides its advantage to absorb hydrogen with very high permeation coefficient, sulfur atom is predicted to be adsorbed in a limited amount.


2021 ◽  
Vol 9 ◽  
Author(s):  
Junbo Zhang ◽  
Xiaodong Lu ◽  
Jingjing Zhang ◽  
Han Li ◽  
Bowen Huang ◽  
...  

Layered structure (MoS2) has the potential use as an anode in metal-ions (M-ions) batteries. Here, first-principles calculations are used to systematically investigate the diffusion mechanisms and structural changes of MoS2 as anode in lithium (Li)-, sodium (Na)-, magnesium (Mg)- and Zinc (Zn)-ions batteries. Li and Na ions are shown to be stored in the MoS2 anode material due to the strong adsorption energies (~−2.25 eV), in contrast to a relatively weak adsorption of Mg and Zn ions for the pristine MoS2. To rationalize the results, we evaluate the charge transfer from the M-ions to the MoS2 anode, and find a significant hybridization between the adsorbed atoms and S atoms in the MoS2 anode. Furthermore, the migration energy barriers of M ions are explored using first-principles with the climbing image nudged elastic band (CINEB) method, and the migration energy barrier is in the order of Zn > Mg > Li > Na ions. Our results combined with the electrochemical performance experiments show that Li- and Na-ions batteries have good cycle and rate performance due to low ions migration energy barrier and high storage capability. However, the MoS2 anode shows poor electrochemical performance in Zn- and Mg-ions batteries, especially Zn-ion batteries. Further analysis reveals that the MoS2 structure undergoes the phase transformation from 2H to 1T during the intercalation of Li and Na ions, leading to strong interaction between M ions and the anode, and thus higher electrochemical performance, which, however, is difficult to occur in Mg- and Zn-ions batteries. This work focuses on the theoretical aspects of M-ions intercalation, and our findings may stimulate the experimental work for the intercalation of multi-ions to maximize the capacity of anode in M-ions batteries.


2010 ◽  
Vol 24 (09) ◽  
pp. 859-865 ◽  
Author(s):  
SHUANG-XI WANG ◽  
YU YANG ◽  
BO SUN ◽  
RONG-WU LI ◽  
SHAO-JUN LIU ◽  
...  

We study the adsorption properties of the N 2 molecule on the Be (0001) surface by calculating the potential energy surfaces and analyzing the electronic densities of states. It is found that the N 2 molecule cannot adsorb molecularly on the clean Be surface, and the dissociation energy barrier of N 2 is estimated to be as large as 4.10 eV. Our studies indicate that the Be surfaces cannot be used as N 2 cleaners, but might be used to drive out N 2 molecules in automotive catalytic converters.


1981 ◽  
Vol 42 (C6) ◽  
pp. C6-625-C6-627 ◽  
Author(s):  
P. E. Van Camp ◽  
V. E. Van Doren ◽  
J. T. Devreese

2021 ◽  
Vol 27 (6) ◽  
Author(s):  
Wen-Guang Li ◽  
Yun-Dan Gan ◽  
Zhi-Xin Bai ◽  
Ming-Jian Zhang ◽  
Fu-Sheng Liu ◽  
...  

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