Boosting light olefin selectivity in CO2 hydrogenation by adding Co to Fe catalysts within close proximity

• Published in: Catalysis today 2021-07, Vol.371, p.142-149
• Main Authors: Yuan, Fei, Zhang, Guanghui, Zhu, Jie, Ding, Fanshu, Zhang, Anfeng, Song, Chunshan, Guo, Xinwen
• Format: Article
• Language: English
• Subjects: CO2 hydrogenation; CoFe2O4; Fe-based catalysts; Lower olefin
• ISSN: 0920-5861; 1873-4308
• DOI: 10.1016/j.cattod.2020.07.072

[Display omitted] •CoFe2O4 was used as a catalyst precursor in CO2 hydrogenation leading to high selectivity toward C2+ hydrocarbons.•High dispersion of iron and cobalt helps to inhibit the formation of methane, while accelerate the formation of long chain products.•The intimate contact between Fe and Co sites favors a higher selectivity of C2+ hydrocarbons. Direct conversion of carbon dioxide (CO2) into lower olefins (C2-C4=) is highly attractive as a sustainable production route for its great significance in greenhouse gas emission control and fossil fuel substitution. Fe-based catalysts have been extensively studied in CO2 hydrogenation, which usually show unsatisfactory selectivity toward lower olefins. Here we present a high-dispersion catalyst precursor CoFe2O4 with Na (Na-CoFe2O4) that offers C2-C4= space time yield as high as 2.88 μmolC2-C4= gcat−1 s-1 and olefin to paraffin ratio about 6 at CO2 conversion higher than 41 %. High dispersion and the intimate contact between Fe and Co sites help inhibit the formation of methane, and favor a higher selectivity of C2+ hydrocarbons, especially lower olefins. The presence of Na further promotes chain growth and suppresses the direct hydrogenation of Fe-(CH2)n intermediates. A superior stability over 100 h was observed, demonstrating the promising potential of this catalyst for industrial applications.