Researchers at the University of Glasgow used a Findenser Super Air Condenser during palladium-catalysed hydrogenation studies investigating selective benzaldehyde conversion to benzyl alcohol.

Overview

Researchers from the University of Glasgow’s Department of Chemistry recently published work investigating the liquid phase hydrogenation of benzaldehyde using supported palladium catalysts. The study explored how catalyst composition and operating conditions influence selectivity towards benzyl alcohol, an important intermediate used in pharmaceuticals, fragrances, vitamins and fine chemicals.

As part of the experimental setup for the ambient pressure reactions, the research team incorporated a Findenser air condenser into their apparatus.

“An air condenser (Radleys Findenser) ensured containment of condensed moieties, while facilitating the release of gaseous hydrogen from the vessel.”

The work, led by Professor David Lennon, examined the performance of several palladium catalyst systems during benzaldehyde hydrogenation. The researchers demonstrated how catalyst loading and support materials significantly affected product selectivity, ranging from high benzyl alcohol selectivity through to complete conversion to toluene under certain conditions.

Simplifying ambient pressure hydrogenation experiments

For ambient pressure studies, the team designed a hydrogenation apparatus based around a 100 mL three-necked round-bottom flask. Hydrogen gas was introduced through a sparging system, while the Findenser acted as the condenser within the setup.

The Findenser enabled efficient condensation of solvent vapours without requiring a continuous water supply, helping simplify the experimental arrangement while maintaining safe venting of hydrogen gas from the reaction vessel. The apparatus was used during studies designed to better understand the transition between hydrogenation and hydrogenolysis pathways under atmospheric pressure conditions.

Investigating selective hydrogenation pathways

The study demonstrated that catalyst choice strongly influenced reaction behaviour. Among the catalysts tested, the 1 wt% Pd/Al2O3 material provided particularly favourable selectivity towards benzyl alcohol.

The researchers also showed that hydrogenolysis to toluene only commenced once benzaldehyde had been fully consumed, helping provide mechanistic insight into the sequential nature of the reaction pathway.

Their findings contribute to a wider understanding of heterogeneous catalytic hydrogenation processes relevant to fine chemical synthesis and biomass valorisation chemistry.

Learn more about the Radleys Findenser and discover how it can simplify reflux workflows in your laboratory.

Link to paper