Effects of sulfur‐ and Fe‐deficient defects on the decomposition of hydrogen peroxide H₂O₂ on pyrite surface

Abstract

There is still a lack of research on the effect of the S and Fe vacancy on the adsorption mechanism of peroxide (H₂O₂) on the pyrite surface. In this work, the adsorption of H₂O₂ molecules on the perfect and defective pyrite surface is simulated based on density functional theory (DFT). The results indicated that the adsorption energy of H₂O₂ molecules on the S‐vacancy surface is relatively lower than that on the perfect surface and dissociative adsorption entirely occurs, while the adsorption behavior of H₂O₂ molecules on the S‐rich pyrite surface has not occurred. When the H₂O₂ molecules are adsorbed on the Fe‐rich pyrite surface, two products appear, one with two OH⁻ species and the other with an H₂O molecule and an O atom. The analysis of the transition state (TS) found that the dissociation of the H₂O₂ molecule producing two OH⁻ species that bond with two Fe atoms is more likely to occur. In addition, based on the coordination chemistry, it is demonstrated that Fe atoms are more reactive around an S vacancy than on a perfect surface.