Pd single-atom catalysts derived from strong metal–support interaction for selective hydrogenation of acetylene

Selective hydrogenation of acetylene in excess ethylene is an important reaction in both fundamental study and practical application. Pd-based catalysts with high intrinsic activity are commonly employed, but usually suffer from low selectivity. Pd single-atom catalysts (SACs) usually exhibit outstanding ethylene selectivity due to the weak π-bonding ethylene adsorption. However, the preparation of high-loading and stable Pd SACs is still confronted with a great challenge. In this work, we report a simple strategy to fabricate Pd SACs by means of reducing conventional supported Pd catalysts at suitable temperatures to selectively encapsulate the co-existed Pd nanoparticles (NPs)/clusters. This is based on our new finding that single atoms only manifest strong metal–support interaction (SMSI) at higher reduction temperature than that of NPs/clusters. The derived Pd SACs (Pd₁/CeO₂ and Pd₁/α-Fe₂O₃) were applied to acetylene selective hydrogenation, exhibiting much improved ethylene selectivity and high stability. This work offers a promising way to develop stable Pd SACs easily.