Details

Autor(en) / Beteiligte

• WU, Da-kai
• WANG, Xu
• GAO, Xin-hua
• MA, Qing-xiang
• ZHANG, Jian-li
• FAN, Su-bing
• ZHAO, Tian-sheng

Titel

Preparation of layered K-Fe-Zn-Ti catalyst and its performance in the hydrogenation of carbon dioxide to light olefins

Ist Teil von

• Journal of fuel chemistry and technology, 2019-08, Vol.47 (8), p.949-956

Ort / Verlag

Elsevier Ltd

Erscheinungsjahr

2019

Quelle

Elsevier ScienceDirect Journals Complete

Beschreibungen/Notizen

• A series of layered K-Fe-Zn-Ti catalysts with different Zn/Fe molar ratios were prepared by high-temperature solid state reaction and characterized by SEM, TEM, XRD, H2-TPR, CO2-TPD, XPS, N2 sorption and TG measurements; the performance of K-Fe-Zn-Ti catalysts in the hydrogenation of CO2 to light olefins was investigated. The results indicate that the K-Fe-Zn-Ti catalysts have the typical layered structure with K2.3Fe2.3Ti5.7O16 as the main phase. ZnFe2O4 appears on the Zn promoted K-Fe-Zn-Ti catalysts, which may reduce the crystallinity, enhance the surface basicity, and promote the adsorption of CO2. The K-Fe-Zn-Ti catalysts exhibit high selectivity to olefins in CO2 hydrogenation; the ratio of olefins to paraffins in the products (O/P) is higher than 6.5. The addition of Zn can enhance the formation of C+ 5 hydrocarbons and especially C+ 4 linear alpha-olefins (LAOs); the content of LAOs in C+ 4 hydrocarbons over Zn promoted K-Fe-Zn-Ti reaches 75.2%, in comparison with the value of 54.6% over the Zn-free K-Fe-Ti catalyst. In particular, the 0.8K-1.8Fe-0.6Zn-1.3Ti catalyst displays the highest O/P value (7.8), although the effect of Zn content in the Zn-promoted K-Fe-Zn-Ti catalysts on the yield of heavy hydrocarbons and selectivity to alpha-olefins is less significant. Moreover, the K-Fe-Zn-Ti catalysts display high stability in CO2 hydrogenation and the LMO structure remains almost intact after a long term reaction test of 100 h.