A Novel Core–Shell Ni/La-Doped Al ₂ O ₃ –ZnO Catalyst with Abundant Oxygen Vacancies for Efficient Elimination of COS

The development of highly efficient and stable catalysts for carbonyl sulfide (COS) hydrolysis is essential for the deep desulfurization of blast furnace gas. In this study, a Ni/La-doped Al2O3–ZnO catalyst with abundant oxygen vacancies was synthesized via a hydrothermal method for enhanced COS hydrolysis. Characterization results indicate that the incorporation of La increased the population of weak and medium-strong basic sites on the catalyst surface. Meanwhile, the incorporation of La promoted electron transfer between Ni3+ and Ni2+, facilitating a proton-coupled electron transfer process and leading to a higher concentration of oxygen vacancies. The oxygen deficiency was shown to significantly enhance the adsorption of COS and promote the dissociation of H2O, with COS preferentially adsorbing at the Ni sites and H2O activation occurring primarily at the La sites. Under reaction conditions of 70 °C and a COS concentration of 540 mg/m3, the Ni–La/Al2O3–ZnO catalyst maintained a COS hydrolysis efficiency exceeding 95% for 8 h. Furthermore, La doping effectively suppressed the sulfation of H2S into sulfate, thereby significantly improving the catalytic stability. This work elucidates the synergistic role of Ni and La in modifying surface basicity and electronic structure, providing a strategic approach for designing high-performance, low-cost catalysts for advanced desulfurization of blast furnace gas.