Hydrodesulfurization catalysts prepared from X(MS4)2-2 thioheteroanions containing Ni or Co and Mo or W : correlation of ESR signal intensity with thiophene conversionanions containing nickel or cobalt and molybdenum or tungsten: correlation of ESR signal intensity with thiophene conversion

Hydrodesulfurization catalysts were prepared by impregnating silica and alumina with aqueous solutions of thioheteroanion complexes containing Ni or Co and Mo or W. Their catalytic activities are comparable to those of conventionally prepared catalysts and the ESR spectra are also very similar. Under H2S/H2 atmosphere the thioheteroanions transform into metal sulfides. Combining the results obtained with catalysts prepared via the new method with those of conventionally prepared catalysts, a larger spread in catalytic activities for thiophene hydrodesulfurization and ESR signal intensities was obtained than for conventional catalysts only. As a result a correlation could be established between the intensity of the ESR signal from Mo3+ and W3+, in interaction with nickel or cobalt promoter ions at the surface of MoS2 or WS2 crystallites, and the catalytic activity for thiophene hydrodesulfurization.