Carbon Nitride-Metal Photocatalyst for Hydrogenation of Acetylene to Ethylene

Ethylene is a key component in plastics synthesis and it is produced by steam cracking of petroleum and naphtha. This process also generates Acetylene as an impurity, which is a potent poison for the polymerization catalysts. The industrial purification process involves a noble metal-based catalyst, a molecular hydrogen co-feed and a high temperature and pressure. These conditions make the catalyst prone to over hydrogenation to ethane. Here is reported an all-in-one photocatalyst based on non-noble metal-carbon nitride system. This system can convert acetylene to ethylene with ≥99.9% selectivity over ethane in non-competitive conditions (no ethylene co-feed), by using water as proton source and visible radiation as energy promoter. These conditions allow a more sustainable acetylene purification without the need for molecular hydrogen and high temperature and pressure.