Cu–Ca–Al catalysts derived from hydrocalumite and their application to ethanol dehydrogenation

Catalysts based on Cu–Ca–Al derived from hydrocalumite were synthesized by continuous coprecipitation and evaluated in ethanol dehydrogenation. Samples were characterized by surface area measurements, XRD, TG/DTA, H2-TPR, NH3-TPD and TPO. The catalytic runs were performed at temperature range of 250–350 °C. For reduced samples, the activation was carried out in situ at 300 °C. The catalysts showed high ethanol conversions and high selectivity for acetaldehyde, either as oxide or metallic phase. The high selectivity for dehydrogenation promoted the reduction of CuO phase to Cu° of unreduced samples during the reaction. The catalysts with high Cu content were deactivated by sintering whereas the catalysts with lower Cu content deactivated mainly by carbon deposition. Acetone is favored by catalysts in the oxide form and with higher Cu content.