First in situ temperature quantification of CoMoS species upon gas sulfidation enabled by new insight on cobalt sulfide formation

Insights into the cobalt sulfide formation upon sulfidation (10 % H2S/H2) of cobalt-based materials with 4 wt CoO supported on alumina or silica were obtained by Quick-X-ray absorption spectroscopy monitoring analysed multivariate curve regression analysis. A common pathway is evidenced involving defective CoS2 species transformed around 200−250 °C Co9S8 species. Upon cooling down under sulfiding atmosphere, a reverse transition towards was observed XAS analysis and Raman This sensitive to crystallite size: smaller nanoparticles higher amount formed after cooling. The knowledge gained monometallic catalysts has been used in order isolate X-ray spectrum CoMoS active during calcined cobalt-promoted HDS catalyst. evolution concentration temperature increase determined for first time, together those pristine oxidic CoMo catalyst, Although conversion still catalyst when decreased H2S/H2 no change percentage evidenced.