Metal–support interactions in Fe–Cu–K admixed with SAPO-34 catalysts for highly selective transformation of CO2 and H2 into lower olefins. Issue 38 (15th September 2021)

• Record Type: Journal Article
• Authors: Ding, Jie; Liu, Qiang; Ye, Run-ping; Gong, Weibo; Zhang, Fan; He, Xiang; Zhang, Yulong; Zhong, Qin; Argyle, Morris D.; Fan, Maohong
• Is Part Of: Journal of materials chemistry. Volume 9:Issue 38(2021)
• Page Start: 21877
• Page End: 21887
• Publication Date: 2021-09-15
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d1ta03327a
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : Strong interactions between Fe–Cu–K and SAPO-34 in admixed catalysts composed of Fe–Cu–K and SAPO-34 result in the changes of structures, reducible properties and mass transfer between Fe-Cu-K and SAPO-34, which contribute to good activities. Abstract : Direct conversion of greenhouse gas carbon dioxide (CO2 ) into lower olefins (ethylene, propylene and butene) provides an appealing approach to tackle CO2 emission challenges. Admixed catalysts composed of metal/metal oxides and SAPO-34 have been widely used for catalytic CO2 hydrogenation to lower olefins. However, interactions between metal/metal oxides and SAPO-34 remain obscure. Here, a novel family of admixed catalysts composed of Fe–Cu–K and SAPO-34 (Fe–Cu–K/SAPO) is developed for efficient catalytic CO2 hydrogenation to lower olefins, which can achieve 49.7% CO2 conversion and 62.9% selectivity of lower olefins, with CO selectivity <10%, over the optimal Fe0.45 Cu0.45 K0.10 /SAPO-34 (with 1/1 mass ratio) catalyst. This exceptional performance is attributed to the change of structures, reducible properties and mass transfer resulting from strong interactions between metal/metal oxides and zeolites. First, SAPO-34 promotes the exposure of the active Cu–Fe (100) plane via disrupting the oriented growth process of Fe–Cu–K. Second, SAPO-34 boosts the reducible properties of Fe–Cu–K/SAPO-34, promoting CO2 adsorption and dissociation and thus resulting in the formation of θ-Fe3 C active sites for hydrocarbon formation. Finally, the main mass transfer method of long-chain hydrocarbons/methanol from Fe–Cu–K to SAPO-34 is gas diffusion, and the dispersion of Fe–Cu–K over SAPO-34 accelerates such gas diffusion. This study provides a potential novel pathway to solve the challenge of efficiently converting CO2 into lower olefins and clarifies the effect of strong interactions between metal/metal oxides and zeolites on activities.