FO5-29/PII.148 Effect of reaction conditions on the product yield in the CO2 hydrogenation reaction over a K-Co-Cu-Al catalyst

Resumo

Converting CO₂ into value-added chemicals is a promising alternative to recent energetic and environmental issues, but designing a non-noble metal catalyst capable of actively and selectively converting CO₂ into desirable products is yet a challenge. Herein, we report on the effect of the reaction conditions on the activity and selectivity of a K-Co-Cu-Al catalyst prepared by a coprecipitation method for the CO₂ hydrogenation to higher alcohols (HAs). We investigated different reduction temperatures, reaction temperatures, space velocities, and H₂/CO₂ ratios to optimize its HAs yield. We observed gains yield of desired products (C2₊ hydrocarbons and HAs) when finding optimum reduction temperature and reducing space velocity and H₂/CO₂ ratio.  K Co Cu Al reduced at 400 ºC exhibits a high HAs selectivity of 45% (21% for ethanol) and space-time yield of 5.6 mmol.h^‑1.g_cat^‑1, under mild conditions (250 °C, 30 bar, H₂/CO₂ ratio of 1.5, and 14200 mL.h^‑1.g_cat^‑1), which represents one of the best performances among related studies, especially amidst Co-based catalysts.