COS and H2S simultaneous removal from blast furnace gas over a tailored Cu/Zr co-doped K@TiO2 bifunctional catalyst under low temperature

The lengthy processes and cumbersome operations for the separate removal of COS and H 2 S have severely limited the development of blast furnace gas recycling process. CuO exhibits excellent H 2 S oxidation performance, but weak COS hydrolysis performance; in contrast, ZrO 2 shows the opposite trend. However, the functional combination of CuO and ZrO 2 has never been used for simultaneous removal of COS and H 2 S. In this study, a Cu/Zr co-doped K@TiO 2 bifunctional catalyst was tailored to simultaneously remove COS and H 2 S. The combined COS and H 2 S capacity of this catalyst reaches 340.5 mg/g at a low temperature of 60 °C, which is much higher than those of other reported bifunctional catalysts. The microcrystal structure formed by Cu/Zr co-doping increases the specific surface area of the catalyst and promotes the adsorption of COS/H 2 S. Specifically, Zr doping increases the content of moderate basic sites and significantly improves the hydrolysis efficiency of COS. Moreover, Cu doping induces lattice distortion of TiO 2 , while CuO captures 4 s valence electrons of K to form Cu 2 O. These two processes lead to the release of lattice oxygen from TiO 2 and CuO, generating oxygen vacancies and ·O 2 − , which promotes H 2 S oxidation. By proposing a simple route for the bifunctionalization of a desulfurization catalyst, this study drives innovation in both the theory and application of simultaneous removal of COS and H 2 S.