Formaldehyde adsorption in carbon nanopores – New insights from molecular simulation

Abstract

Adsorption of formaldehyde is profoundly affected by both the pore structure and the surface chemistry of an adsorbent. Understanding the mechanism of adsorption of formaldehyde in carbonaceous materials at the molecular level is instrumental for the rational design of suitable adsorbents. While most experimental studies have focused on the synthesis and modification of adsorbent materials, the key question of how formaldehyde adsorbs at the microscopic level remains unanswered. To this end, we have conducted a comprehensive Monte Carlo simulation of formaldehyde adsorption in functionalized carbon nanopores and have compared our molecular model with experimental data. The effects of the functional group density and distribution, pore size, and temperature were investigated with the detailed analysis of the isotherm, the isosteric heat and the density distribution, and we particularly highlight the importance of the guest-guest and guest-host interactions. Our investigation also includes a special study of adsorption at ultralow pressures, typically found in practical applications, and provides insight in the search for an effective and water-resistant adsorbent for formaldehyde.