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(2) nanoparticles (NPs) modified with copper oxides (Cu(x)O(y)/TiO(2)) were synthetised via laser pyrolysis. The atmosphere of synthesis (He or Ar) strongly affects the morphology of photocatalysts and therefore their selectivity towards hydrocarbons (C(2)H(4), C(2)H(6), C(4)H(10)) and H(2) products. Specifically, Cu(x)O(y)/TiO(2) elaborated under He environment presents highly dispersed copper species and favours the production of C(2)H(6) and H(2). On the contrary, Cu(x)O(y)/TiO(2) synthetised under Ar involves copper oxides organised into distinct NPs of ~2 nm diameter and promotes C(2)H(4) as the major hydrocarbon product, with selectivity, i.e., C(2)H(4)/CO(2) as high as 85% versus 1% obtained with pure TiO(2).