Highly selective conversion of CO2 to light olefins via Fischer-Tropsch synthesis over stable layered K–Fe–Ti catalysts

• Published in: Applied catalysis. A, General Vol. 573; pp. 32 - 40
• Main Authors: Wang, Xu, Wu, Dakai, Zhang, Jianli, Gao, Xinhua, Ma, Qingxiang, Fan, Subing, Zhao, Tian-Sheng
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 05.03.2019; Elsevier Science SA
• Subjects: Alkenes; Carbon dioxide; Catalysis; Chemical synthesis; CO2 hydrogenation; Fischer-Tropsch process; Hydrocarbons; Hydrogenation; Iron carbides; Iron oxides; Layered K–Fe–Ti catalyst; Light olefins; Olefin adsorption; Paraffins; Reduction; Selectivity; Shift reaction; Titanium; Water gas; Light olefins; Layered K–Fe–Ti catalyst; CO2 hydrogenation; Olefin adsorption
• ISSN: 0926-860X; 1873-3875
• DOI: 10.1016/j.apcata.2019.01.005

[Display omitted] •Stable K–Fe–Ti layered structure catalysts were prepared employing solid phase reaction.•60% of C2=–C4= selectivity was achieved from CO2-FTS reaction over layered K–Fe–Ti catalysts.•Improved performance was contributed to inhibiting secondary reaction of primary olefins by weakening olefin re-adsorption. K–Fe–Ti layered metal oxides (LMO) were prepared using solid-state reaction followed by in situ reduction and applied in CO2 hydrogenation to light olefins via Fischer-Tropsch synthesis process. The results showed that the molar ratio of K/Fe/Ti had dramatic effects on the textural and structural properties of the LMO and the catalytic performance. Layered structure K–Fe–Ti exhibited high olefin selectivity and stability for CO2 hydrogenation. The light olefin selectivity reached approximately 60% with an olefin/paraffin value of 7.3 over 0.8K–2.4Fe–1.3Ti, and the exfoliated LMO through acid treatment was found to weaken the interaction between Fe and Ti. This enabled the reduction and activation of iron oxides easier to form iron carbide species and promoted a shift from the reverse water gas shift reaction regime to hydrocarbon synthesis regime, contributing to higher hydrocarbons while lower CO.