Pt/ZrO2/TiO2 catalysts for selective hydrogenation of crotonaldehyde: Tuning the SMSI effect for optimum performance Original Research Article

Gas phase hydrogenation of crotonaldehyde was performed over Pt/ZrO2/TiO2 catalysts with different zirconia loadings, subjected to low- and high-temperature calcination (200 and 400 °C) and a range of reduction temperatures (200–600 °C). Pt/TiO2 was used as reference system. The catalysts were characterised by TPR, XPS, SEM, HR TEM, TOF-SIMS and H2, O2 and CO chemisorption after different stages of thermal pretreatments. The relationship between catalytic activity, selectivity towards crotyl alcohol and physicochemical properties of the catalysts was examined. The catalyst containing 30% ZrO2 in the support, calcined at 200 °C and reduced at 500 °C showed the highest selectivity (50%) while retaining good activity. The explanation of those properties was proposed, involving the mutually opposing action of two factors – presence of ZrO2 and ‘permeability’ of Pt phase for TiOx migration – in controlling of the SMSI effect.