CO catalytic oxidation on Pt-doped single wall boron nitride nanotube: First-principles investigations

Abstract

The catalytic oxidation of CO at Pt-doped BNNT (5,5) has been investigated theoretically using density functional theory. The electronic structures and thermochemical properties of CO and O 2 that adsorbed on Pt embedded at the B- and N-vacancy sites of BNNTs are analyzed. It is demonstrated that the different BNNT substrates can modify the electronic structure of the Pt catalysts and cause different effects in the catalytic activities. With the N-vacancy (Pt (N) -BNNT), the Pt behaves as a Lewis acid for accepting an electron from the substrate, thus O 2 binds stronger than CO molecules, thus alleviating the CO poisoning of the platinum catalysts. Coadsorption of CO and O 2 on Pt (N) -BNNT results in additional charge transfer to O 2. CO oxidation proceeds via the Eley-Rideal (ER) mechanism entails lower activation barrier and higher reaction rate than that of Langmuir-Hinshelwood (LH) mechanism suggesting the superiority of the ER mechanism for CO oxidation at Pt (N) -BNNT. Therefore, Pt (N) -BNNT might be a good candidate for low-cost, highly active, and stable catalysts for CO oxidation.