The mechanism governing the temperature dependence of the dissociation products in the thermal decomposition of formic acid on the anatase TiO₂(101) surface is identified by systematically and automatically exploring reaction path networks for clean, protonated, and oxygen-deficient surfaces.

Abstract

In this study, the reaction pathways for the thermal decomposition of formic acid on the anatase TiO₂ (101) surface were systematically investigated. The investigation was carried out using a single-component artificial force induced reaction method that combines density functional theory calculations. In order to uncover the overall mechanism at low surface coverage, we explored reaction path networks for three different conditions of the anatase TiO₂ (101) surfaces: clean, protonated, and oxygen-deficient surfaces. Previous temperature-programmed desorption (TPD) experiments had shown that H₂O desorption starts at a low temperature of about 300 K, while CO and formaldehyde desorption starts at high temperatures of about 500 K. The present reaction path networks are consistent with the overall trend observed in the TPD experiments. Using the reaction pathways extracted from these networks, the overall dissociation mechanism has been discussed.