Synthesis of three-dimensional ordered mesoporous W-doped KIT-6 for oxidative desulfurization catalyst of fuels

A W-KIT-6 catalyst is prepared by inserting tungsten into the KIT-6 framework to reduce the amount of tungsten and improve the catalyst stability and using it for the oxidative desulfurization (ODS) reaction. Raman and UV-visible spectroscopic analyzes confirm that tungsten is successfully embedded in the KIT-6 framework, and WO3 is formed at high tungsten content. X-ray photoelectron spectroscopy uncovers that tungsten is present in the form of W6+ and W5+ in the framework. High-resolution transmission electron microscopy, nitrogen adsorption-desorption measurements and small-angle X-ray diffraction confirm the ordered structure of the W-KIT-6 catalyst. The true amount of tungsten in the catalyst is measured by inductively coupled plasma spectrometry. The dispersion of tungsten in the catalyst is analyzed by transmission electron microscopy element mapping. The W-KIT-6 catalytic activity is evaluated in the ODS reaction using simulated oil. Under optimal conditions, the sulfur removal effect can reach 100%. Catalyst recovery experiments show that the catalytic activity remains unaltered after 15 cycles, indicating the good stability of the catalyst. The catalytic reaction mechanism is also analyzed.