Caracterização de γ – alumina e estudos fundamentais da adsorção de CO2, DME e metanol

Abstract

As greenhouse emissions increase, new ways to turn around their atmosphere presence are more needed than ever. Speaking of CO2, a method that gives it a purpose as a reagent and proves its capture to be a lucrative action is its conversion to DME, a clear alternative to diesel fuel which implementation shows large advantages. In this chemical process, γ – alumina acts as e fundamental catalyst in one of the reaction steps. The substance also finds applications in separation processes by adsorption and filtration as a nano porous membrane. It is also a desirable substance as a catalyst support. Even though there already are studies aimed at its bulk and surface structure determination, information about its characterization with regards to pore size distribution is still lacking in the literature. This research performs pore size distribution (PSD) calculations using Monte Carlo computer simulations. For such, γ-alumina pores with diameters ranging from 7,0 to 53,0 angstroms were designed using a catalyst molecular model from literature. Argon was the probe molecule chosen and the calculations with it were in good accordance with previously performed experiments. The heats of adsorption for the reactions core reagents and product were also estimated since for these data, literature is also hard to deliver. Quantic calculations based on the density theory functional (DFT) were performed employing the B3LYP functional and the double ζ 6-31G(d) basis set.