Adsorption of Benzene on the RuO2(110) Surface

TL;DR

This study uses density functional theory to analyze how benzene molecules adsorb onto RuO2(110) surfaces, revealing how oxygen coverage affects adsorption strength, which is key to understanding hydrocarbon layer formation in MEMS/NEMS devices.

Contribution

It provides a detailed computational analysis of benzene adsorption on RuO2(110) considering oxygen coverage and van der Waals interactions, advancing understanding of tribopolymer formation mechanisms.

Findings

Benzene adsorbs more strongly on O-poor RuO2(110) via C-Ru bonds.

Adsorption strength varies with oxygen coverage on the surface.

Including van der Waals interactions offers a more comprehensive understanding.

Abstract

Hydrocarbon tribopolymer, a type of polymer formed due to friction between surfaces, is a major impediment to the development of micro- and nanoelectromechanical systems (MEMS/NEMS) devices for industrial application. Tribopolymer buildup can prevent MEMS and NEMS from making or breaking electrical contact. We describe the adsorption of benzene (C6H6) on the RuO2(110) surface using density functional theory. This adsorption is an important initial step in the mechanism of hydrocarbon tribopolymer layer formation on MEMS and NEMS devices. The adsorption interaction is studied by considering three oxygen coverages of RuO2(110) and all the possible adsorption sites for benzene. We find that adsorption of benzene on O-poor RuO2(110) via C-Ru bonds is stronger than adsorption on the O-rich RuO2(110) via H-O bonds. For an in-depth study of the adsorption behavior, we include the van der Waals interaction for a holistic investigation. By incorporating the thermodynamic chemical potentials into the adsorption simulations, we describe a model that can provide guidance for realistic situations.