Support Effects on the Activity and Selectivity of Ni₃CuSn_0.3 Trimetallic Catalysts in the Selective Hydrogenation of Phenylacetylene

Supported Ni-based catalysts present a promising alternative to precious Pd-based catalysts for the selective hydrogenation of phenylacetylene due to their abundance and cost-effectiveness. However, the influence of support materials on the catalytic performance of Ni-based catalysts has been insufficiently explored. In this study, a series of Ni₃CuSn_0.3 trimetallic catalysts (Ni:Cu:Sn molar ratio of 3:1:0.3; Ni loading of 20 wt %) supported on various materials, including SiO₂, SBA-15, Al₂O₃, MgO, CeO₂, and TiO₂, were synthesized, characterized, and evaluated. In general, silica-supported catalysts showed higher hydrogenation activity but lower styrene selectivity, while metal oxide-supported catalysts exhibited reduced activity but enhanced selectivity. The catalytic activity decreased with increasing Sn incorporation into the Ni-Cu alloys, whereas styrene selectivity was affected by both electronic and geometric effects. Among the catalysts tested, Ni₃CuSn_0.3/Al₂O₃ demonstrated the highest styrene selectivity at complete phenylacetylene conversion. This catalyst was further prepared via a scalable solvent-free ball milling method, achieving an initial reaction rate of 4.5 mmol/(g·min) and 95% styrene selectivity at complete phenylacetylene conversion under 60 °C and 0.5 MPa. Moreover, it displayed stable performance over multiple reaction cycles, with the properties remaining well-preserved. These results offer new opportunities for developing large-scale processes for the selective hydrogenation of phenylacetylene using earth-abundant catalysts.