A study on the catalytic performance of the ZrO2@γ-Al2O3 hollow sphere catalyst for COS hydrolysis

Abstract

In order to achieve the catalytic removal of COS gas from blast furnace gas by hydrolysis, it is necessary to obtain a hydrolysis catalyst with excellent performance. A hollow sphere hydrolysis catalyst with low catalytic energy consumption, long catalytic life and high conversion COS efficiency was prepared by using carbon spheres as a template and urea as a precipitant to increase the alkalinity of the impregnating solution to overcome the shortcomings of limited adsorption of a carbon sphere template. The structural characteristics of the prepared Al₂O₃ hollow sphere hydrolysis catalyst were first analyzed; then different proportions of zirconium nitrate were loaded onto the surface of the Al₂O₃ hollow spheres to investigate the effect of the formed ZrO₂@γ-Al₂O₃ hollow sphere hydrolysis catalyst on the catalytic performance of COS hydrolysis. The results showed that the average pore size, total pore volume and specific surface area of the ZrO₂@γ-Al₂O₃ hollow sphere hydrolysis catalyst roasted at 500 °C reached the maximum, with 12.921 nm, 0.177 cm³ g⁻¹ and 52.969 m² g⁻¹, respectively. The hydrolytic catalytic efficiency of COS was highest when the roasting temperature was 500 °C. After 70 min of reaction, the hydrolytic conversion efficiency of COS remained at about 82% with a conversion of 158 mg m⁻³. The key problems of low catalytic activity and short catalytic life of hydrolysis catalysts can be effectively solved when using hydrolysis catalysis for the removal of COS.