New Application of Glycerin from a Photochemical Approach:  Dihydrogen Formation from Aqueous Glycerin by Use of Giant Polyoxometalate Photocatalysts

Photocatalytic H 2 formation from aqueous glycerin was achieved over giant polyoxometalate complexes Na 21 K 4 [{P 2 W 15 Ti 3 O 57.5 (OH) 3 } 4 Cl]·104H 2 O and Na 18 H 15 [{P 2 W 15 Ti 3 O 59 (OH) 3 } 4 {μ 3 -Ti(OH) 3 } 4 Cl]·105H 2 O to develop a new application for glycerin, an oversupplied compound accompanying biodiesel production. This is the first example of the catalytic formation of H 2 by use of a photocatalyst and glycerin and is also the first example of a photochemical application of giant polyoxometalate complexes. The catalytic reactions proceed at room temperature under irradiation with UV−visible light without the use of any cocatalyst. The reaction mechanism can be explained by redox reactions between the complexes, water, and glycerin.