Influence of the Pt-particle size on the performance of carbon supported catalysts used in the hydrogenation of citral

• A carbon xerogel was selected as Pt-support to avoid catalytic interferences.
• The Pt-particle size was the unique variable used.
• The optimum Pt-particle size was detected for particles at around 8 nm.
• The unsaturated alcohol yield increased mainly due to an activity increase.
• Steric hindrance favours the geranial conversion regarding the neral one.

The influence of the Pt-particle size in the selective citral hydrogenation is analysed. For that, a Pt/Carbon catalyst has been prepared by impregnation of a carbon xerogel and pre-treated in different conditions to obtain particle sizes varying from 3 to 10 nm. The Pt particle size has been deeply characterized by HRTEM, XRD, XPS and H2 chemisorption and related with the catalytic performance in each case. Both activity and selectivity to the valuable unsaturated alcohols are favoured for catalysts with increasing Pt-particle size up to around 8 nm, decreasing for larger particles. In this sense, the interaction and transformation of geranial (E-citral) is also favoured regarding neral (Z-citral).

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