Effect of pretreatment of iron catalyst on light olefin selectivity in CO hydrogenation

Effects of CO and H₂ pretreatment on the Fe₂O₃ catalyst and its catalytic performance on the light olefin production through CO hydrogenation were investigated. It was indicated that the catalyst sample pretreated with H₂ at 300℃ favored the formation of Fe₃O₄ and α-Fe phases. Fe₃O₄ was formed with CO pretreatment at 250℃. And, with the increase of pretreatment temperature, iron carbides were formed. The TPD experiment showed that the surface basicity of the catalyst pretreated with CO was stronger than that with H₂. Surface carbonaceous deposition caused decrease of CO₂ and CO adsorption. Comparing to H₂ pretreated catalyst, CO pretreated catalyst has higher selectivity to light olefins.