Boron nitride nanotube confining selected platinum group metal (PGM=Pd and Pt) single atoms catalysts for efficient CO oxidation: Theoretical insight into confinement effect.

[Display omitted] • Platinum group metal atoms confined on the surfaces of BNNT(6,6) with N-vacancy show high stability. • Pt confined inside BNNTs with N-vacancy turns out to be the candidate for CO oxidation, with energy barrier of 0.28 eV via the Langmuir–Hinshelwood mechanism and 0.35 eV. • Spatial confinement effect of BNNT(6,6) contributes to charge transfer between Pt and adsorbed gas, which promotes activation of O 2 and CO. Despite platinum group metal have been widely used in catalytic converters, high cost and reaction temperature hindered their application. Inspired by the single-atom catalysts and confinement effect, selected PGM confined on the boron nitride nanotube with vacancy defects for CO oxidation have been systematically investigated. For PGM–BNNT catalysts, CO oxidation would proceed competitively in Eley–Rideal and Langmuir–Hinshelwood pathways. With N vacancy, Pd/Pt-BNNT(6,6) needs 0.33 and 0.28 eV to overcome the reaction barriers through the LH mechanism. The internal of BNNT will provide a more favorable nano-confinement environment than exterior surface, with the more activated adsorbed gases and electron transfer. [ABSTRACT FROM AUTHOR]