Assessing the Potential of Amorphous Silica Surfaces for the Removal of Phenol from Biofuel: A Density Functional Theory Investigation

Abstract

Biofuels may contain phenolic molecules, which are toxic for humans and can significantly affect engine performance. In this context, amorphous silica surfaces are attractive since they have the potential to separate the harmful molecules from the biofuel constituents through a selective adsorption process. Here, density functional theory is employed to describe the different adsorption modes of toluene and phenol, chosen as model molecules, on amorphous silica surfaces with various silanol densities. It is found that surfaces with densities of 2.0, 3.3, and 4.6 OH/nm 2 are optimal to trap phenol, with certain configurations attaining an adsorption energy of more than 100 kJ/mol. These trends remain similar at 300 K as shown by our molecular dynamics simulations, although the interaction energy between the molecules and the surface is reduced due to the temperature.

Balancing computational chemistry's potential with its environmental impact

“…[10][11][12] Furthermore, investigations into the production of green hydrogen, required for this methanol production, have been carried out via DFT 13,14 and molecular dynamics. 15,16 There is no shortage of publications utilizing these computational tools for a variety of other climate-relevant processes, such as CO 2 absorption with metal-organic frameworks, 17,18 recycling of chlorine for polyvinyl chloride production, 19,20 biofuel production, 21,22 and material discovery. 23 Additionally, Jain et al 24 provided a comprehensive review of the application of DFT for energy materials like batteries, photovoltaics, and capacitors.…”

Mechanocatalytic Hydrogenolysis of the Lignin Model Dimer Benzyl Phenyl Ether over Supported Palladium Catalysts

“…While silica supports are generally considered inert, it has been shown that chemisorption of alcohols readily occurs at defect sites that are formed when silica ruptures during milling (Figure S11). − In addition to chemisorbed phenolates on such defect sites, phenol can physisorb onto silanol sites. − The physisorbed phenols are more easily removed and comprise most of the phenol yield that was observed after washing. This ultimately suggests that the Lewis acid site concentration plays a minor role in absorption.…”