Ti-SBA-15 supported Cu–MgO catalyst for synthesis of isobutyraldehyde from methanol and ethanol

Ti-SBA-15 supported Cu and MgO catalysts were prepared and used for the first time in the one-step conversion of methanol and ethanol to isobutyraldehyde (IBA). The results show that the loadings of Cu and MgO, and catalyst calcination temperature have strong effects on the catalyst activity. A high yield of IBA, 32.7%, and high ethanol conversion, 96.6%, were achieved at 360 °C with WHSV of 3.0 mL (g−1 h−1) on the catalyst calcined at 400 °C when the loadings of Cu and Mg were 20.0 wt% and 6.5 wt%, respectively. The physicochemical properties of the catalysts were analyzed by various techniques including XRD, N2 adsorption and desorption, FT-IR, H2-TPR, CO2-TPD and XPS. The ordered mesoporous structure of the catalysts was retained with the introduction of CuO and MgO. The size of CuO particles on the catalysts was retained though they suffered from a varied calcination temperature. H2-TPR measurements revealed that the increase of calcination temperature from 400 °C to 700 °C resulted in the decrease of basicity of the catalysts, and enhanced the interaction between the Cu and Mg species and the support. The results from XPS analysis indicated that the binding energy of Cu 2p was increased with the introduction of MgO, while the increased calcination temperature easily resulted in the decrease of Cu content on the catalyst surface due to probable migration of Cu species into internal pores or their incorporation into the framework of the Ti-SBA-15 support.