Hydrophobic RWGS catalysts: Valorization of CO2-rich streams in presence of CO/H2O

• Published in: Catalysis today 2023-11, Vol.423, p.114276, Article 114276
• Main Authors: Tarifa, P., González-Castaño, M., Cazaña, F., Monzón, A., Arellano-García, H.
• Format: Article
• Language: English
• Subjects: Biogas; Doped-carbon supports; Fe catalysts; H2O; Hydrophobic; Reverse water gas shift
• ISSN: 0920-5861; 1873-4308
• DOI: 10.1016/j.cattod.2023.114276

Nowadays, the majority of the Reverse Water Gas Shift (RWGS) studies assume somehow model feedstock (diluted CO2/H2) for syngas production. Nonetheless, biogas streams contain certain amounts of CO/H2O which will decrease the obtained CO2 conversion values by promoting the forward WGS reaction. Since the rate limiting step for the WGS reaction concerns the water splitting, this work proposes the use of hydrophobic RWGS catalysts as an effective strategy for the valorization of CO2-rich feedstock in presence of H2O and CO. Over Fe-Mg catalysts, the different hydrophilicities attained over pristine, N- and B-doped carbonaceous supports accounted for the impact on the activity of the catalyst in presence of CO/H2O. Overall, the higher CO productivity (4.12 μmol/(min·m2)) attained by Fe-Mg/CDC in presence of 20 % of H2O relates to hindered water adsorption and unveil the use of hydrophobic surfaces as a suitable approach for avoiding costly pre-conditioning units for the valorization of CO2-rich streams based on RWGS processes in presence of CO/H2O. [Display omitted] •N- or B- doping improves the Fe-Mg/CDC performance for the RWGS in presence of CO and H2O.•Fe-Mg/CDC attained higher CO productivity due to promoted CO2 adsorptions.•A higher ratio of Mg/Fe could improve the resistance against water.•B-doped catalyst displays higher conversion in presence of CO.