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Effect of lanthanum loading in Fe-K/La-Al2O3 catalysts for CO2 hydrogenation to hydrocarbons

2000; Wiley; Volume: 14; Issue: 12 Linguagem: Inglês

10.1002/1099-0739(200012)14

1099-0739

Sang‐Sung Nam, Gurram Kishan, Myoungwoo Lee, Myoung‐Jae Choi, Kyu-Wan Lee,

Catalysis and Hydrodesulfurization Studies

Lanthanum-modified alumina supports prepared by the impregnation method have been used as supports for potassium-promoted iron catalysts in CO2 hydrogenation. The catalysts have been characterized by X-ray diffraction, CO2 chemisorption, temperature-programmed reduction (TPR) and temperature-programmed decarburization (TPDC) techniques. The selectivity towards total hydrocarbons and lower olefins (C2–C4) was found to increase with increase in lanthanum content up to 4 wt% in Fe–K/La–Al2O3 catalysts and to decrease above this lanthanum content. The TPR profiles of the catalysts of lanthanum-modified Al2O3 shows the reduction of Fe2O3 to iron(0) follows a three-stage reduction mechanism through formation of the FeO phase. The TPDC profiles show the formation of three types of carbide species on the catalysts during the reaction. The activities of the catalysts are correlated with physico-chemical characteristics of the catalysts. Copyright © 2000 John Wiley & Sons, Ltd.