ZnO/SiO2 gel composites with different active component loading were prepared by sol-gel method combined with ambient drying process, followed by thermal treatment. The gel composites were characterized by scanning electron microscopy (SEM), nitrogen adsorption, X-ray diffraction (XRD), FTIR and X-ray photoelectron spectroscopy (XPS), and their performances for H2S removal were evaluated by dynamic testing at room temperature. The as prepared materials exhibited high surface area with multi-modal pore size distributions in micropore and mesopore region. The porous properties were significantly influenced both by the ZnO loading ratio and the treated temperature. The gel composites showed a high performance for H2S removal, with the highest H2S adsorption capacity of 96.4 mg/g for the sample treated at 400 degrees C with 30 wt% ZnO. Both physisorption and the active phase reactivation governed the H2S removal process. It needs to optimize the composites' porous structure and active component loading amount. (C) 2012 Elsevier B.V. All rights reserved.