In situ DRIFTS combined with GC–MS to identify the catalytic oxidation process of dibenzofuran over activated carbon-supported transition metals oxide catalysts

Emission of polychlorinated dibenzop-dioxins and polychlorinated dibenzofurans (PCDD/Fs) have exerted more and more pressure on humans and the environment. The catalytic oxidation has been a good selection for eliminating dioxin in industries. Carbon-based catalysts were great potential to alleviate dioxin because of their large surface area and low cost. Catalytic oxidation of dioxin over metal oxide catalysts M/AC (M = V, Fe, Cu, Mn) was evaluated, and V/AC showed the highest catalytic activity at 300 °C. The catalysts surface acid amounts were improved through loading metal oxide, especially the Lewis acid, which could promote DBF adsorption on catalysts. Combined in-situ FTIR with GC–MS, two different reaction paths were provided on V/AC and Cu/AC catalyst. The C–C bond of DBF was priority broken to be oxidized on V/AC, and main transformation of DBF was from benzofuran, phenol and maleic acid to final products. The C–H bond of DBF was firstly activated on Cu/AC, and large unstable quinone species were produced. The main transformation of DBF was from DBF- quinone, benzofuran, furan to final products on Cu/AC. In this work, detailed reaction paths and by-products of DBF oxidation were provided.