In this work, a series of substituted heteropoly compounds (HPCs) were synthesized and dissolved into ionic liquid 1-N-butyl-3-methylimidazolium chloride (BmimCl) to be used for H2S removal at 200 degrees C. The absorbent and desulfurization product were characterized by elemental analysis, Fourier transform infrared (FT-IR) spectra, Thermogravimetry analysis (TGA), Differential Scanning Calorimetry (DSC) and X-ray photoelectron spectroscopy (XPS). The absorption results showed that the desulfurization ability of Mo-V doped HPC is far better than that of W-Mo doped HPC, which demonstrated that Mo and V in HPC are more suitable for H2S removal compared with W atom. Besides, [Bmim]PMo10V2O40/BmimCI solution showed the best desulfurization performance. The regeneration experiment showed that all HPC/IL solution can be recycled easily. The desulfurization mechanism could be expressed as: H2S + O-2 ->(HPC/IL) H2O + S. Never was found before in liquid phase, the oxygen in HPC could be replaced by S2-, which tremendously improved the sulfur capacity. (C) 2017 Elsevier B.V. All rights reserved.