The role of vanadium species during SO2 removal over a V2O5/AC catalyst

Abstract

The role of vanadium species during SO₂ removal over a V₂O₅/AC catalyst was studied in detail using in situ diffuse reflectance infrared Fourier transform spectroscopy, Raman spectroscopy, temperature programmed desorption, X-ray photoelectron spectroscopy and N₂ adsorption. Results revealed that V₂O₅ reacted with SO₂ to form a stable vanadium(V) sulfate of V₂O₃(SO₄)₂. However, V₂O₃(SO₄)₂ did not deactivate the catalyst and was catalytically active towards SO₂ oxidation, leading to the formation of H₂SO₄. Thus, the sulfur capacity of the V₂O₅/AC catalyst was determined by formation of V₂O₃(SO₄)₂ and H₂SO₄. Increasing V₂O₅ loading enhanced the formation of V₂O₃(SO₄)₂ but inhibited that of H₂SO₄ because V₂O₃(SO₄)₂ occupied the pores for H₂SO₄ storage.