Synergetic effect dependence on activated oxygen in the interface of NiOx modified Pt nanoparticles for CO oxidation from first-principles

Author(s):  
Zihang Yao ◽  
Jiaqiang Yang ◽  
Zhang Liu ◽  
Bin Shan ◽  
Rong Chen ◽  
...  

CO oxidation on NiOx-modified Pt nanoparticles (NPs) is investigated by first-principles calculations and microkinetic methods. The binding energies of O2 and CO on NiOx/Pt suggest that CO adsorption is dominated...

RSC Advances ◽  
2017 ◽  
Vol 7 (77) ◽  
pp. 48819-48824 ◽  
Author(s):  
Mingguang Wang ◽  
Zhu Wang

We have investigated the potential catalytic activity of a single Ni atom incorporated with pyridinic nitrogen graphene (Ni-3N-G) in CO oxidation with first-principles calculations.


2009 ◽  
Vol 1177 ◽  
Author(s):  
Bin Shan ◽  
Jangsuk Hyun ◽  
Neeti Kapur ◽  
Kyeongjae Cho

AbstractAlloying has been one of the strategies to develop alternatives to Pt based CO oxidation catalyst. PdAu bimetallic alloy has recently been shown to have better reactivity and thermal stability toward CO oxidation for diesel engine applications as compared to pure metal catalysts. The key factor for low temperature light off in diesel engine catalysis is reactivity of alloy catalysts under CO environment, which in turn depends on the alloy surface composition and morphology. We explored the segregation processes in bimetallic Pd-Au alloy using first-principles calculations, assisted by a Monte-Carlo (MC) scheme that combines an improved Embedded Atom Method (EAM) and an atomistic treatment for adsorbed CO molecules for searching low energy states. Our simulation results show that PdAu surface changes from Au-rich to Pd-rich with increase in CO coverage up to 0.75 ML, beyond which additional CO adsorption is no longer favorable. A quantitative relationship between CO coverage and Pd concentrations on the surface is also revealed.


2002 ◽  
Vol 752 ◽  
Author(s):  
C. Guizard ◽  
C. Levy ◽  
L. Dalmazio ◽  
A. Julbe

ABSTRACTRecent data from the literature dealing with the influence on oxygen transport of porous nanophase ion conducting ceramics are reviewed, and then transposed to the design of mesoporous nanophase ceria-based membranes. Mesoporous CeO2/Al2O3 and Gd doped CeO2 membranes containing Pd and Pt nanoparticles were prepared using the sol-gel process. Permeation of N2 and O2 single gases was studied in a temperature range 20–500°C. Permeation measurements indicate an activated oxygen transport in agreement with the literature data. A synergetic effect of the noble metal nanoparticles on oxygen transport has been evidenced, in relation with the triple phase boundary concept. However, these membranes do not perform totally the preferential oxygen transport predicted by the theory. Several directions are proposed for membrane improvement, in particular concerning pore and grain optimal sizes.


2019 ◽  
Vol 21 (23) ◽  
pp. 12201-12208 ◽  
Author(s):  
Ranganathan Krishnan ◽  
Shiuan-Yau Wu ◽  
Hsin-Tsung Chen

We performed a systematic study of CO oxidation on a single Pt atom supported on penta-graphene (Pt/PG) by utilizing spin-polarized first-principles calculations. The results manifested that Pt/PG, as a single-atom catalyst, exhibited excellent catalytic activity toward CO oxidation and provided a novel strategy for the design of single-atom catalysts based on penta-graphene.


RSC Advances ◽  
2014 ◽  
Vol 4 (58) ◽  
pp. 30530-30535 ◽  
Author(s):  
Qiuju Zhang ◽  
Baihai Li ◽  
Houyuan Wang ◽  
Yange Suo ◽  
Liang Chen

In the present work, we investigated the structural and catalytic properties of a prototype system Pt-doped CaTiO3 by means of first principles calculations.


Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 279
Author(s):  
Wei-Feng Sun ◽  
Yu-Xuan Sun ◽  
Shu-Ting Zhang ◽  
Ming-He Chi

The complex configuration, H2 adsorption binding energy, magnetic, and optical properties of FAU zeolites with Ag cations loaded by ion exchange in the vacant dielectric cavities were investigated by employing the first-principles calculations with all-electron-relativistic numerical atom-orbitals scheme and the Metropolis Monte Carlo molecular simulations. The visible absorption spectrum peaked at distinct wavelengths arranging from red or green to blue colors when changing the net charge load, due to the produced various redox states of Ag cations exchanging at multiple Li+-substituted sites. The spin population analyses indicate the ferrimagnetic coupling between Al–O–Si framework and Ag cations originates from the major ferromagnetic spin polarization in Ag cation cluster coordinating with sodalite cages, with the net spins appreciably depending on the Ag content and exchange site. The H2 adsorption capacities and binding energies represent significant dependence on the content, location, and electronic property of Ag cations introduced into the FAU zeolites. The evident decrease of H2 adsorption binding energy with increased loading concentration demonstrates repulsive interaction between H2 molecules and heterogeneous adsorption configuration on Ag cations. The adsorption sites of H2 sorted by the binding energy with different adsorption configurations were correlated with exchange sites of Ag cations under different Ag loading to comprehend the H2 adsorption mechanism.


2018 ◽  
Vol 20 (48) ◽  
pp. 30403-30411 ◽  
Author(s):  
J. Matthias Kahk ◽  
Johannes Lischner

C1s and O1s core level binding energy shifts have been calculated for various adsorbates on Cu(111) using the ΔSCF method.


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