Hydrogen sulfide (H 2 S), a toxic and corrosive gas, poses significant environmental and health risks. The selective catalytic oxidation of H 2 S to elemental sulfur has emerged as an attractive and sustainable solution for purification. In this work, a facile, template-free approach is developed to synthesize hierarchically porous UiO-66-Fe (HP-UiO-66-Fe) featuring abundant coordinatively unsaturated Fe/Zr dual-metal sites. The controlled competition between water and acetic acid as modulators directs the formation of the hierarchical pore architecture, while the asymmetric coordination between Fe and Zr generates numerous coordinatively unsaturated sites. The resulting HP-UiO-66-Fe demonstrates exceptional catalytic performance in H 2 S oxidation, achieving complete H 2 S conversion and nearly 100% sulfur selectivity across a broad temperature window. Through integrated structural characterization and catalytic performance evaluation, we reveal that the outstanding activity originates from the synergistic interplay between the unsaturated Fe/Zr bimetallic sites and the hierarchical porous framework, which collectively promote reactant activation, facilitate mass transport and strengthen sulfur poisoning resistance. This study not only presents a highly efficient catalyst for H 2 S abatement but also proposes a general design strategy for engineering multifunctional MOF catalysts via coupled bimetallic defect creation and pore-structure regulation. Hierarchical porous UiO-66-Fe with unsaturated Fe/Zr dual-metal sites is synthesized via a template-free method. This architecture synergistically boosts reactant activation and mass transport, achieving highly selective H 2 S oxidation to elemental sulfur. • A facile, template-free strategy utilizing water and acetic acid as dual modulators enables the synthesis of hierarchically porous UiO-66-Fe. • Hierarchically porous UiO-66-Fe features abundant coordinatively unsaturated Fe/Zr dual-metal sites • HP-UiO-66-Fe achieves complete H 2 S conversion with remarkable stability. • The integration of reactant-activating unsaturated bimetallic sites and transport-facilitating hierarchical porosity drives the enhanced performance.
Zhang et al. (Sun,) studied this question.