Selective oxidation of allylic alcohols over highly ordered Pd/meso-Al2O3 catalysts

• Highly ordered mesoporous alumina was used as a catalyst support.
• Alumina impregnation yielded highly dispersed and heavily oxidised Pd nanoparticles.
• Surface palladium oxide was identified as the active species in allylic alcohol selox.
• Pd/meso-Al2O3 is exceptionally active towards diverse allylic alcohol substrates.

Highly ordered mesoporous alumina was prepared via evaporation induced self assembly and was impregnated to afford a family of Pd/meso-Al2O3 catalysts for the aerobic selective oxidation (selox) of allylic alcohols under mild reaction conditions. CO chemisorption and XPS identify the presence of highly dispersed (0.9–2 nm) nanoparticles comprising heavily oxidised PdO surfaces, evidencing a strong palladium-alumina interaction. Surface PdO is confirmed as the catalytically active phase responsible for allylic alcohol selox, with initial rates for Pd/meso-Al2O3 far exceeding those achievable for palladium over either amorphous alumina or mesoporous silica supports. Pd/meso-Al2O3 is exceptionally active for the atom efficient selox of diverse allylic alcohols, with activity inversely proportional to alcohol mass.