Analysis of the adsorption characteristics of gasification pollutants (HCl, COS, H2S, NH3 and HCN) on Ti-anchored graphene substrates

Abstract

The adsorption characteristics of HCl, COS, H2S, NH3 and HCN (coal gasification pollutants) on the adsorbents (single vacancy, double vacancy, and doped nitrogen atoms) formed by the graphene substrates anchored with titanium atom were analyzed by density functional theory (DFT) calculation. This paper mainly analyzed the geometric configuration of the adsorbent, the adsorption configuration of the gas, and the adsorption energy and the magnetic properties. And through the analysis of the electron density difference and the projected density of states (PDOS), the adsorption mechanism of five coal gasification pollutants on different adsorbents were deeply studied. The calculated results indicate that HCl, COS, H2S, NH3 and HCN can be adsorbed on Ti/SV-N3 graphene adsorbent, and the values of the adsorption energy were −1.07 eV, −1.73 eV, −0.28 eV, −0.41 eV, and -1.23 eV, respectively. Moreover, the introduction of nitrogen atoms significantly enhanced the interaction between single-atom graphene and gas molecules. Based on theoretical results, Ti/SV-N3 was the most suitable for simultaneous removal of these five pollutant gasses, which can guide the development of new materials for pollutant gas removal.