Effect of Phosphorus Modification on Cu−ZnO−Al 2O 3 for the Removal of H 2S

Abstract

Cu−Zn−Al oxides adsorbents with or without phosphorus modification have been investigated for their hydrogen sulfide removal efficiency. Cu 0.46Zn 0.48/γ-Al 2O 3 was prepared by precipitating Cu and Zn nitrate precursors on unmodified and phosphorus-modified γ-Al 2O 3. For the preparation of Cu 0.46Zn 0.48/1P/γ-Al 2O 3, Cu 0.46Zn 0.48/3P/γ-Al 2O 3, and Cu 0.46Zn 0.48/9P/γ-Al 2O 3, the γ-Al 2O 3 was previously modified with different amounts of phosphorus (1, 3, and 9 wt %, taken in the form of phosphoric acid) and Cu and Zn precursors were precipitated in the slurry of it. The sorbents were characterized by X-ray diffraction (XRD), surface area, pore size distribution, temperature-programmed reduction (TPR), Cu surface area measurement, and X-ray photoelectron spectroscopy (XPS). The sorbent modified with 3 wt % P on γ-Al 2O 3 showed the maximum value for the sulfur removal capacity and a large surface area of Cu. This high value of Cu surface area mainly results from making a sorbent with large pore diameter. Reduction in the binding energy of Cu 2P of the well-dispersed Cu metal particles, as observed by XPS analysis, could be the reason for the high sulfur removal capacity.