Catalytic reduction of SO2 by Gd@CeOx catalysts: stability enhancement and structural modulation

Abstract

The production of sulfur by catalytically reducing SO₂ with CO presents a promising approach for utilizing sulfur oxides found in flue gases. While the novel desulfurization technique exhibits commendable attributes such as heightened efficacy and economical feasibility, its progression is hampered by challenges of catalyst poisoning-induced service life constraints. In this work, the optimization of the Gd@CeO_x catalyst prepared by a hydrothermal process aimed to enhance its resistance to poisoning. The results reveal that the catalyst achieved a conversion of 71.6% and a sulfur yield of 64.6% after a 72 h reaction at 400 °C. This notable performance is ascribed to the hydrothermal synthesis of more porous structures, which improve gas adsorption and activation, as well as increase the presence of alkali on the surface of the Gd@CeO_x catalyst. The reaction mechanism follows both L–H and E–R pathways. This work offers a cost-effective and efficient approach to flue gas desulfurization, with substantial implications for sulfur resource utilization.