One-Step Synthesis of Cu x O y /TiO 2 Photocatalysts by Laser Pyrolysis for Selective Ethylene Production from Propionic Acid Degradation.

In an effort to produce alkenes in an energy-saving way, this study presents for the first time a photocatalytic process that allows for the obtention of ethylene with high selectivity from propionic acid (PA) degradation. To this end, TiO nanoparticles (NPs) modified with copper oxides (CuO/TiO) were synthetised via laser pyrolysis. The atmosphere of synthesis (He or Ar) strongly affects the morphology of photocatalysts and therefore their selectivity towards hydrocarbons (CH, CH, CH) and H products. Specifically, CuO/TiO elaborated under He environment presents highly dispersed copper species and favours the production of CH and H. On the contrary, CuO/TiO synthetised under Ar involves copper oxides organised into distinct NPs of ~2 nm diameter and promotes CH as the major hydrocarbon product, with selectivity, i.e., CH/CO as high as 85% versus 1% obtained with pure TiO.