CO2 Hydrogenation to Light Olefins Over In2O3/SAPO-34 and Fe-Co/K-Al2O3 Composite Catalyst

Direct CO2 conversion to light olefins offers a chance to reduce CO2 emission with generating the revenue. However, a lack of efficient catalysts is a barrier for promoting this technology to an industrial scale. Here, we report a new catalytic system using a composite catalyst containing In2O3/SAPO-34 and Fe-Co/K-Al2O3 to enhance the light olefins yield. The effect of catalysts bed configuration including a physical mixture of In2O3/SAPO-34 with Fe-Co/K-Al2O3 (M-InS/Fe-Co), a dual-layer packing of In2O3/SAPO-34 followed by Fe-Co/K-Al2O3 (T-InS/B-FeCo) and a dual-layer packing of Fe-Co/K-Al2O3 above In2O3/SAPO-34 (T-FeCo/B-InS) is investigated. The M-InS/Fe-Co and T-FeCo/B-InS catalysts show a light olefins yield of 11.5 and 16.2% which are lower than that (18.9%) of the single Fe-Co/K-Al2O3 catalyst. A drastic reduction in the BET surface area (42 m(2) g(-1)) of M-InS/Fe-Co catalyst compared to its theoretical value of 198 m(2) g(-1) is observed, suggesting the pores blockage. The T-InS/B-FeCo composite catalyst achieves a state-of the art light olefins yield of 21.5% due to a selective CO2 conversion to light olefins over In2O3/SAPO-34 and a highly active CO2 conversion to hydrocarbon over Fe-Co/K-Al2O3 which further converts the remaining CO2 from the former catalyst bed to light olefins and other hydrocarbon products until equilibrium CO2 conversion is reached.

Automated summary

Direct CO2 conversion to light olefins is an opportunity to reduce emissions and generate revenue, but the lack of efficient catalysts hinders industrial scale implementation. A new composite catalyst system has been developed to enhance light olefins yield, offering a potential solution to this barrier.