Photoelectrochemistry of Levulinic Acid on Undoped Platinized n-TiO2 Powders

Article abstract of DOI:10.1021/j100239a026

The photoelectrochemistry of levulinic (4-oxopentanoic) acid, the major product of controlled degradation of cellulose by acids, has been investigated.Since this acid can be present in waste streams of biomass processing, we investigated the photoelectrochemical reactions of this acid on slurries composed of semiconductor/metal particles.The semiconductor investigated was platinized undoped n-TiO2, as anatase, anatase-rutile mixture, or rutile.The effects of the level of platinization, pH, acid concentration, and the semiconductor surface area were investigated.In addition to the decarboxylation reaction leading to methyl ethyl ketone, we have also observed novel cleavages of the C-C backbone leading to propionic acid, acetic acid, acetone, and acetaldehyde as major products.These lower molecular weight carboxylic acids undergo decarboxylation at the slurry diodes to ethane and methane.The organic product distribution is a complex function of the crystallographic phase of n-TiO2 and of the level of metallization of the semiconductor powder.