Effect of EDTA-2Na modification on Fe-Co/Al2O3 for hydrogenation of carbon dioxide to lower olefins and gasoline. Issue 43 (January 2021)

• Record Type: Journal Article
• Authors: Dai, Chengyi; Zhao, Xiao; Hu, Borui; Zhang, Xinbao; Luo, Qunxing; Guo, Xinwen; Ma, Xiaoxun
• Is Part Of: Journal of CO₂ utilization. Issue 43(2021)
• Publication Date: 2021-01
• Subjects: Lower olefins -- Gasoline -- Ethylenediaminetetraacetic acid disodium salt -- CO2 hydrogenation; Carbon dioxide -- Periodicals; Carbon dioxide -- Environmental aspects -- Periodicals; Carbon dioxide mitigation -- Periodicals; Carbon dioxide; Carbon dioxide -- Environmental aspects; Carbon dioxide mitigation; Periodicals; 628.53205
• DOI: 10.1016/j.jcou.2020.101369
• Languages: English
• ISSNs: 2212-9820

Abstract

Highlights: CO2 was hydrogenated to lower olefins and gasoline using EDTA-2Na-modified catalysts. EDTA-2Na contributed to enhance the sintering resistance of catalysts. EDTA-2Na modification is favorable for catalyst reduction. Chemical adsorption of CO2 is enhanced using EDTA-2Na-modified catalysts. The catalysts prepared by this strategy are suitable for a low H2 /CO2 ratio. Abstract: Capturing and utilization of carbon dioxide (CO2 ) not only leads to effective use of carbon resources, but also alleviates environmental pollution caused by increasing concentration of CO2, thus making it a hot research topic in recent years. In this study, a series of highly dispersed iron-cobalt (Fe-Co) catalysts was prepared by ethylenediaminetetraacetic acid disodium salt (EDTA-2Na) modification, which could efficiently convert CO2 into high value-added chemicals (C2 -C4 = and C5 -C11 ). X-ray diffraction (XRD) analysis showed that the addition of a small amount of Co and EDTA-2Na contributed to enhance the sintering resistance of Fe species. During the calcination process, EDTA 4− can be decomposed into small organic molecules with reducibility, thus promoting the reduction of iron species. The CO temperature-programmed desorption (CO-TPD) results showed that cobalt enhanced the adsorption and activation of intermediate CO on Nax Fe-Co catalyst, thereby promoting the catalytic conversion of CO2 . The complexation of EDTA promotes the synergistic effect of Fe-Co bimetals, enhances the chemical adsorption of CO2 . Sodium in EDTA-2Na promotes the surface basicity of the catalysts, which is favored for improving the product distribution of hydrocarbons. At lower H2 /CO2 (1/1) ratio, the EDTA-2Na modified Fe-Co/Al2 O3 catalyst exhibited high conversion of CO2 (32.8 %) and excellent selectivity toward high value-added chemicals. The selectivity of by-product CO was only 8.1 %; and C2 -C4 = (32.5 %) and C5 -C11 (46.3 %) accounted for ∼79 % selectivity among the hydrocarbons generated.