X-ray photoelectron spectroscopy surface quantification of sulfided CoMoP catalysts. Relation between activity and promoted sites. Part II: Influence of the sulfidation temperature

The effect of the sulfidation temperature on the nature and amount of active phases of CoMoP-type hydrodesulfurization catalysts was investigated. An X-ray photoelectron spectroscopy quantification approach was developed, allowing us to show a direct relation between the amount of mixed CoMoS active phase as determined by XPS and the catalytic activity. XPS, transmission electron microscopy (TEM) and toluene-hydrogenation activity correlations also showed that the sulfidation temperatures should range between 350 and 500 degrees C. Under these conditions the catalysts are mainly composed Of MoS2 and CoMoS active phases and present a maximum of activity. Copyright (C) 2006 John Wiley & Sons, Ltd.