Dual cobalt speciation in Co/ZSM-5 catalysts*1

摘要: Abstract X-Ray diffraction, X-ray photoelectron spectroscopy, and infrared spectroscopy are used to investigate cobalt speciation in Co ZSM -5 catalysts containing 1.4 9.5 wt% cobalt. These catalysts, metal-impregnated using incipient wetness techniques with Co(NO3)2 · 6H2O, shown contain highly dispersed, ion-exchanged, non-reducible Co2+ species interior the ZSM-5, large, reducible oxide crystallites on exterior of ZSM-5 crystallite surface. The number ions located inside a unit cell pyridine molecules that coordinately bond each these estimated by data characterizing chemisorption. crystalline forms surface identified their sizes after O2 calcination, H2 reduction, CO + exposure. then scrutinized for correlations chemical physical properties conversion activity selectivity synthesis hydrocarbons from gas.