Significantly enhanced surface oxygen vacancies over W18O49 via Mo doping and plasma-induced surface reconstruction for oxidative desulfurization

Abstract

The non-stoichiometric structure of tungsten oxide (W18O49) makes it easy to form oxygen vacancies near the low-valence W atoms, so the W18O49 can be applied to oxidative desulfurization. To further improve the desulfurization activity of W18O49 to meet the increasingly stringent environmental requirements, Mo doping and plasma-induced surface reconstruction cooperative strategies are developed. The incorporation of Mo species into the W18O49 surface by replacing W sites can adjust the atomic and electronic structure of the catalyst surface and form more oxygen vacancies. After Mo doping into the W18O49, the plasma bombarded the surface of material to destroy part of the surface structure, thus producing the reactive sites with low coordination numbers. This reconstructed atomic surface also accompany to generate more oxygen vacancies, thus greatly improving the catalytic activity. Compared to pure W18O49, significantly improves oxidative desulfurization performance can be achieved over Mo-W18O49-P, and deep desulfurization is realized within 3 h. Moreover, the optimal Mo-W18O49-P shows better stability than pure W18O49, which can be recycled for 12 times. This work provides an accessible pathway for cooperative enhancing the catalytic oxidative desulfurization activity of oxide catalysts.