Abstract: A more active and heat resistant water gas shift catalyst Co Mo K/Al₂O₃ has beenobtained by modification of Al₂O₃ support with La₂O₃ (ranging from 0.5 to 1 wt. % basedon the catalyst) and aftertreatment at 600℃. La-promoted catalyst lost～50% of itsinitial activity after water gas shift reaction which is accelerated at 500℃, while theunpromoted catalyst lost～70%. The activity of deteriorated catalyst can be restored bytreatment with H₂S/H₂, but the rate of reactivation of the La-promoted is greater thanthat of the unpromoted. No obvious difference was found in the sulfidation of catalystwith H₂S/H₂ and temperature programmed reduction determination and pyridine adsorptionon sulfided catalyst. XPS data indicated that a better dispersion of Mo and less Mo⁶⁺ formed during water gas shift reaction on the La-promoted catalyst.

Key words: Cobalt molybdenum catalyst, Water gas shift, Lathanum promoter, Sulfur resistant