Efficient catalytic degradation of chlorinated volatile organic compounds by porous graphitized carbon supported CuFeS2 via activation of hydrogen peroxide

Abstract

Here, a CuFeS<inf>2</inf>/PGC catalyst was prepared by hydrothermal method using CuCl, FeCl<inf>3</inf>·6H<inf>2</inf>O and (NH<inf>4</inf>)<inf>2</inf>S as raw materials, and a CuFeS<inf>2</inf>/PGC-H<inf>2</inf>O<inf>2</inf> wet scrubber system was constructed and applied to the degradation of dichloroethane (DCE). When the dosages of CuFeS<inf>2</inf>/PGC catalyst and hydrogen peroxide (H<inf>2</inf>O<inf>2</inf>) were 0.2 g/L and 20 mM, respectively, the removal efficiency of 25 ppmv DCE was still as high as 85.7 % at 500 min. The electrochemical results and X-ray photoelectron spectroscopy (XPS) indicated that the CuFeS<inf>2</inf>/PGC catalyst could supply electrons to Cu²⁺, Fe³⁺, and H<inf>2</inf>O<inf>2</inf>. The CuFeS<inf>2</inf>/PGC catalysts with S²⁻and S<inf>2</inf>²⁻ as electron donors promoted the efficient cycling of Fe³⁺/Fe²⁺ and Cu²⁺/Cu⁺, which sustained the H<inf>2</inf>O<inf>2</inf> activation and DCE degradation in the CuFeS<inf>2</inf>/PGC-H<inf>2</inf>O<inf>2</inf> system. In addition, the HO^• and O<inf>2</inf>^•− were confirmed to be the main active species using electron spin resonance (ESR) and quenching experiments. The Fe(II)-S species of iron on the catalyst surface was identified as the main active site for H<inf>2</inf>O<inf>2</inf> activation. Finally, the CuFeS<inf>2</inf>/PGC catalyst exhibited good stability and cycling performance for the degradation of a variety of Chlorinated volatile organic compounds (CVOCs) and ion solubilization experiments, and the system has some broad application prospects.