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Interfacial‐Bonding‐Regulated CO Oxidation over Pt Atoms Immobilized on Gas‐Exfoliated Hexagonal Boron Nitride
Author(s) -
Liu Xin,
Zhu Hongdan,
Linguerri Roberto,
Han Yu,
Chambaud Gilberte,
Meng Changgong
Publication year - 2017
Publication title -
chemistryselect
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 34
ISSN - 2365-6549
DOI - 10.1002/slct.201701663
Subject(s) - dangling bond , hexagonal boron nitride , catalysis , boron nitride , materials science , boron , bond cleavage , nitride , crystallography , atom (system on chip) , chemistry , nanotechnology , layer (electronics) , metallurgy , organic chemistry , graphene , silicon , computer science , embedded system
We compared the electronic structure and CO oxidation mechanisms over Pt atoms immobilized by both B‐vacancies and N‐vacancies on gas‐exfoliated hexagonal boron nitride. We showed that chemical bonds are formed between the B atoms associated with dangling bonds around the vacancies and Pt atoms. These bonds not only alter the thermodynamics and kinetics for the aggregation and effectively immobilize Pt atoms, but also significantly change the composition and energetic distribution of the electronic states of the composites to circumvent CO poisoning and to favour coadsorption of CO and O 2 , which further regulates the reactions to proceed through a Langmuir‐Hinshelwood mechanism. The CO oxidation over Pt atoms immobilized at N‐vacancies involves formation of an intermediate with –C(O)‐O−O‐ bonded to Pt, the generation of CO 2 by peroxo O−O bond scission and the reduction of the remnant oxygen, and the calculated energy barriers are 0.49, 0.23 and 0.18 eV, respectively. Such small energy barriers are comparable to those over Pt atoms trapped at B‐vacancies, showing the effectiveness of Pt/hexagonal boron nitride atomic composites as catalysts for CO oxidation. These findings also suggest the feasibility of regulating the reaction pathways over single atom catalysts via interfacial engineering.