Catalytic Conversion for Hydrogen Sulfide

In this study, a series of transition metal mono-substituted heteropoly compounds H_7PMo_(11)MO_(39) (M = Co^(2+), Mn^(2+), Ni^(2+) and Zn^(2+)) (HPMo_(11)M) and single-absent heteropoly compounds H_3PMo_(11)O_(39) (HPMo_(11)) were prepared for highly effective removal of hydrogen sulfide (H_2S) from gas stream. The heteropoly compounds were characterized Fourier transform infrared spectroscopy (FT-IR), elemental analysis and scanning electron microscopy (SEM). The results confirmed that the transition metal ions successfully replaced the Mo atom. H_7PMo_(11)CoO_(39) showed that the outstanding desulfurization capacity and the H_2S removal efficiency can reach more than 90% for 3 h. Besides, after regeneration, the desulfurization capacity of H_7PMo_(11)CoO_(39) towards H_2S only a drop of 5.11% of the initial desulfurization capacity. Optimization experiments demonstrated that H_7PMo_(11)CoO_(39) had the ideal desulfurization performance under the condition of low H_2S concentration or high dosage of H_7PMo_(11)CoO_(39). An appropriate temperature of 25°C is necessary for high removal efficiency. The optimum pH value for desulfurization is 5. The kinetic data can be well described by pseudo-first-order kinetic model. The desulfurization products were proved to be S and SO_4^(2-) based on X-ray photoelectron spectroscopy (XPS) characterization results.