Photocatalysis in Action: Oxidizing Alcohols with [(TiOH)PW11O40]4- (A02 – Ö01)

This project tests two polyoxometalates, phosphotungstic acid (PW12) and phosphomolybdic acid (PMo12), against vanillyl alcohol and cinnamyl alcohol under UV light. Both undergo a reversible redox colour change ("heteropoly blue") while the resulting aldehyde gives a distinct smell, letting students see directly that a catalyst is not consumed, that different catalysts behave differently, and that colour and smell are independent signs of reaction progress. As a complementary system, we have also confirmed that a Ti-doped POM reliably oxidizes vanillyl alcohol to vanillin, offering an optional third comparison catalyst for advanced groups.