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Theoretical insights on the influence of doped Ni in the early stage of graphene growth during the CH4 dissociation on Ni–Cu(1 1 1) surface

Paper ID Volume ID Publish Year Pages File Format Full-Text
39037 45802 2015 7 PDF Available
Title
Theoretical insights on the influence of doped Ni in the early stage of graphene growth during the CH4 dissociation on Ni–Cu(1 1 1) surface
Abstract

•The doped Ni not only retain their activity but also improve the activity of its surrounding Cu atoms.•H2 pressure and temperature have opposite influence on the branching rate of CH4 dissociation on Ni–Cu(1 1 1) surface.•The doped Ni has little influence for C migration while depresses the polymerization process on the neighbouring Cu atoms.

CH4 dissociation on the Ni doped Cu(1 1 1) surface has been studied theoretically. Our results show that the doped Ni not only maintains its own activity, but also improves the activity of neighbouring surface Cu atoms during CH4 dissociation. The microkinetic analysis demonstrate that the coverage of CH3 becomes higher than that of CH on surface Ni when H2/CH4 ratio is larger than 1, while the coverage of CH3 on Cu atom is nearly the same when H2 is introduced. With the increase of temperature, the branching rate of Ni increases, while that of Cu decreases. Compared with temperature, opposite behavior is found with the increase of H2/CH4 ratios. Furthermore, the behavior of C atom on Ni–Cu(1 1 1) is discussed. The doped Ni has little influence for C migration, while it depresses the polymerization process on the neighbouring Cu atoms. Free C atoms produced by CH4 dissociation prefer to dissolve on the site having subsurface Ni atom. Once within the bulk, the C atom will move toward the site where surface Ni exists. Then it will dissolve out to contribute the formation of graphene.

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Keywords
CH4 dissociation; Catalytic activity; DFT-D2; Microkinetic model; Reaction mechanism; Ni doping
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Theoretical insights on the influence of doped Ni in the early stage of graphene growth during the CH4 dissociation on Ni–Cu(1 1 1) surface
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Publisher
Database: Elsevier - ScienceDirect
Journal: Applied Catalysis A: General - Volume 506, 5 October 2015, Pages 1–7
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Catalysis
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us