Unveiling the Remarkable Catalytic Performance of Al2O3@Cu-Ce Core–Shell Nanofiber Catalyst for Carbonyl Sulfide Hydrolysis at Low Temperature

Carbonyl sulfide represents a significant organic sulfur impurity in furnace gas, and its removal can enhance the economic value of furnace gas. In this study, a series of Al-based core–shell nanofiber catalysts were synthesized and employed for the catalytic hydrolysis of COS. The Al₂O₃@Cu-Ce catalyst demonstrated a 100% COS conversion efficiency at a gas hourly space velocity of 15 000 h⁻¹ at 70°C. The interaction of Cu and Ce can enhance their dispersion and facilitate the formation of micropores. The formation of Cu₂Al₄O₇ and CeAlO₃ resulted in a reduction in the number of micropores and effective active components on the catalyst surface. The primary catalytic roles were played by Cu²⁺ and Ce³⁺. The high content of adsorbed state oxygen O_β and suitable water resistance resulted in enhanced hydrolysis performance. The Al₂O₃ shell layer is capable of effectively protecting the Cu and Ce components from being covered and consumed, thereby prolonging the lifetime of the catalyst. The addition of Cu resulted in alterations to both the weakly and moderately basic sites, whereas the addition of Ce primarily affected the weakly basic sites. The formation of Cu-O-Ce increased the percentage of CuO in the Cu fraction, thereby enhancing the COS removal performance. There is a competitive adsorption relationship between COS and H₂S on the CuO (002) surface. COS, H₂O, and H₂S compete for adsorption on the O_v-CeO₂ (111) surface. O_v-CeO₂ (111) promotes the dissociation of H₂O and the generation of -SH groups. The hydrolysis process of COS occurs in steps on CuO (002) and O_v-CeO₂ (111).