XAFS study on the sulfidation mechanisms of Co-Mo catalysts supported on activated carbon and alumina: effect of complexing agent

The effect of nitrilotriacetic acid (NTA) as a complexing agent on the sulf idation mechanisms of Co-Mo catalysts supported on activated carbon and alu mina was examined by the XAFS technique. The XAFS results revealed that NTA interacted with Co atoms and formed the Co-NTA interaction, while it showe d almost no influence on the local structures around Mo atoms. The Co-NTA i nteraction suppressed the aggregation of cobalt atoms and the interaction b etween cobalt and alumina during sulfiding, and consequently promoted the f ormation of the Co-Mo-S phase.