Highly Ordered Mesoporous Fe2O3–ZrO2 Bimetal Oxides for an Enhanced CO Hydrogenation Activity to Hydrocarbons with Their Structural Stability

• Published in: ACS catalysis Vol. 7; no. 9; pp. 5955 - 5964
• Main Authors: Cho, Jae Min, Lee, Sae Rom, Sun, Jian, Tsubaki, Noritatsu, Jang, Eun Joo, Bae, Jong Wook
• Format: Journal Article
• Language: English
• Published: American Chemical Society 01-09-2017
• Subjects: ordered mesoporous Fe2O3−ZrO2 oxides; stable χ-Fe5C2; Fischer−Tropsch synthesis; structural stability; structural promoter of ZrO2
• ISSN: 2155-5435; 2155-5435
• DOI: 10.1021/acscatal.7b01989

Highly ordered mesoporous Fe2O3–ZrO2 mixed bimetal oxides (FeZr) without any additional chemical promoters were first applied to produce the value-added hydrocarbons by CO hydrogenation through Fischer–Tropsch synthesis (FTS) reaction of syngas. To enhance a catalytic activity and structural stability, an irreducible ZrO2 as a structural promoter was incorporated in the ordered mesoporous Fe2O3 structures with a different Zr/Fe molar ratio from 0 to 1 prepared by using a hard template of KIT-6. When an optimal amount of zirconia (Zr/Fe molar ratio = 0.25) was incorporated in the ordered mesoporous Fe2O3 frameworks, the catalytic activity was significantly improved and almost 10 times higher than the mesoporous monometallic Fe2O3. The highly ordered mesoporous structures were stably preserved even under reductive FTS reaction conditions. The ordered mesoporous FeZr catalysts showed a higher C5+ selectivity even at a higher CO conversion above 80%. This improved catalytic activity and stability on the optimized FeZr catalyst were mainly attributed to the facile formation of active iron carbide species such as the stable χ-Fe5C2 with insignificant structural collapses through a formation of strongly interacted iron nanoparticles with the ZrO2 structural promoter with a suppressed inactive coke deposition in the highly ordered FeZr mesopores.