Adsorption of Acid, Ester, and Ether Functional Groups on Pt: Fast Prediction of Thermochemical Properties of Adsorbed Oxygenates via DFT-Based Group Additivity Methods

Abstract

Density functional theory (DFT) calculations are utilized to systematically study the geometric and energetic trends of adsorbed carboxylic acid, ether, and ester intermediates on Pt(111). Specifically, the properties of formic acid, acetic acid, propionic acid, isobutyric acid, dimethyl ether, ethyl methyl ether, isopropyl methyl ether, methyl formate, methyl acetate, and their dehydrogenation intermediates are calculated. Subsequent statistical mechanical calculations are performed to reveal systematic trends in thermochemical properties of oxygenate adsorbates on Pt(111). These trends are utilized to develop and parametrize a new semiempirical group additivity scheme that can be used to predict thermochemical properties of acids, ethers, esters, alcohols, aldehydes, and hydrocarbons and their decomposition intermediates on Pt(111). This scheme is both rapid and accurate and can easily be implemented as a tool to parametrize and screen large oxygenate reaction mechanisms for identification of important reaction steps that can subsequently be refined with more accurate computational methods.