A new story for aryl alkynes removal in excess alkenes by supported AuPd

The purification and elimination of traces of alkynes in alkenes is significant important in industrial chemistry. For the traditional semi-hydrogenation route to remove alkynes, however, the hydrogenation of alkenes cannot be avoided due to their similar properties (e.g. styrene and phenylacetylene). In this work, we found that the supported AuPd nanoparticles could selectively adsorb and polymerize aryl alkynes with the styrene untouched. At 60 °C, the removal capability was up to 169.2 mmol/g_(AgPd) for phenylacetylene, whereas 0 mmol/g_(AgPd) for styrene. In the presence of excess styrene, the concentration of phenylacetylene can be easily decreased from 10 ppm to 2.5 ppm. No activity was observed for pure Au, Pd and other metal alloy counterparts. Control experiments showed that both benzene ring and C≡C bond are essential for the molecular adsorption on AuPd surface. Spectroscopy investigations and theoretical calculations confirmed the interaction between phenylacetylene and AuPd. The supported AuPd nanomaterial could be recovered by washing with ethyl alcohol or hydrogenating the removed alkynes. This new finding opens an avenue for designing highly efficient systems for alkenes purification. © 2025 Elsevier B.V.