Under-cover stabilization and reactivity of a dense carbon monoxide layer on Pt(111)

Igor Píš,Silvia Nappini,Elena Magnano,Federica Bondino

doi:10.1039/c8sc04461a

Igor Píš, Silvia Nappini + Show 2 more

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https://doi.org/10.1039/c8sc04461a

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Abstract

The space between a metal surface and a two-dimensional cover can be regarded as a nanoreactor, where confined molecule adsorption and surface reactions may occur. In this work, we report CO intercalation and reactivity between a graphene-hexagonal boron nitride (h-BNG) heterostructure and Pt(111). By employing high resolution X-ray photoemission spectroscopy (XPS) we demonstrate the molecular intercalation of the full h-BNG overlayer and stabilization of a dense R23.4°-13CO layer on Pt(111) under ultra-high vacuum at room temperature. We provide experimental evidence of a weakened CO-metal bond due to the confinement effects of the 2D cover. Temperature-programmed XPS results reveal that CO desorption is kinetically delayed and occurs at a higher temperature than on bare Pt(111). Moreover, CO partially reacts with the h-BNG layer to form boron-oxide species, which affect repeated CO intercalation. Finally, we found that the properties of the system towards interaction with CO can be considerably recovered using high temperature treatment.

Highlights

A two-dimensional (2D) layer containing carbon (C), boron (B) and nitrogen (N) in a continuous honeycomb network is a promising new material with wide range applications in the elds of electronics, gas sensors, or heterogeneous catalysis
The h-BNG/Pt(111) sample was exposed to CO in the UHV chamber
It has been proposed that the diffusion of molecular species into interfaces between metals covered by full sp2-hybridized layers happens through structural defects, such as pinholes,[20] grain boundaries[21,22] or wrinkles.[23]

Summary

Introduction

A two-dimensional (2D) layer containing carbon (C), boron (B) and nitrogen (N) in a continuous honeycomb network is a promising new material with wide range applications in the elds of electronics, gas sensors, or heterogeneous catalysis.

Results

Conclusion