Interfacial‐Bonding‐Regulated CO Oxidation over Pt Atoms Immobilized on Gas‐Exfoliated Hexagonal Boron Nitride. Issue 29 (12th October 2017)

• Record Type: Journal Article
• Authors: Liu, Xin; Zhu, Hongdan; Linguerri, Roberto; Han, Yu; Chambaud, Gilberte; Meng, Changgong
• Is Part Of: ChemistrySelect. Volume 2:Issue 29(2017)
• Page Start: 9412
• Page End: 9419
• Publication Date: 2017-10-12
• Subjects: CO -- Defects -- h-BN -- Monovacancy -- Oxidation -- Pt -- Single Atom Catalysis; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/slct.201701663
• Languages: English
• ISSNs: 2365-6549

Abstract

Abstract: 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 O2, 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 CO2 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. Abstract : The interfacial Pt−B interactions significantly change the composition and energetic distribution of the electronic states of Pt atoms immobilized by N‐vacancies on h‐BN, enabling them to exhibit a stronger affinity to O2 to circumvent CO poisoning, and make the CO oxidation through a Langmuir‐Hinshelwood mechanism efficient.