Modulating oxygen vacancies of Fe-doped Ti-based materials with ultrathin nanosheets for enhancing H2S-to-S selective oxidation

Abstract

Developing highly efficient catalysts for the transformation of hydrogen sulfide (H2S) pollutants into value-added products is crucial for both fundamental catalytic research and industrial chemistry. Herein, ferrititanate nanosheets (H0.8Ti1.2Fe0.8O4, denoted as NS-HTFO) exfoliated from lepidocrocite-type titanates are employed for the first time to catalyze the conversion of H2S to elemental sulfur. Collective experimental characterizations reveal that the as-designed NS-HTFO catalyst possesses ultrathin 2D structure and a large specific surface area, featuring abundant oxygen vacancies. Compared with its sandwich-like precursor of K0.8Ti1.2Fe0.8O4 (denoted as L-KTFO), the NS-HTFO catalyst displays notably enhanced desulfurization activity, achieving 100 % H2S conversion and over 93 % sulfur selectivity at temperatures ranging from 90 to 270 °C. Moreover, no significant decline in sulfur yield is observed over the course of a 100-hour evaluation, showing outstanding breakthrough sulfur capacity up to 4163 mg/gcat. This performance exceeds that of most recently reported catalysts. The possible catalytic mechanism for H2S-to-S selective oxidation over the NS-HTFO catalyst has also been investigated.