Nickel-doped CuxO/Al2O3 catalyzes oxidation of H2S at near ambient temperature: Performance evaluation and mechanism exploration

Abstract

A series of Ni-doped CuxO/Al2O3 catalysts were developed for catalytic oxidation of H2S, and catalytic conditions of Ni content, temperature and humidity were optimized by measuring H2S performance. The surface of the catalyst doped with Ni (2.5 wt%) exhibited three-dimensional (3D) nano-network structure, largest number of basic sites and oxygen vacancies (VOs). Ni-Cu synergistic effect improved desulfurization capacity of H2S by catalysts at near ambient temperature. 3D nano-network structure provided more sulfur storage space. Basic sites from NiO and VOs from CuxO effectively enhanced catalyst-H2S interaction by hydroxylating H2O, thus promoting dissociation and oxidation of H2S, eventually resulting in a high desulfurization capacity (334.3 mg/g). Desulfurization reaction product was mainly S (91.0%), and by-products were mainly sulfate and CuS. Additionally, our synthesized catalyst can realize sulfur recovery. Therefore, Ni-doped CuxO/Al2O3 is a promising H2S removal catalyst at low temperature.