High Performance of Single-atom Catalyst Pd1/MgO for Semi-hydrogenation of Acetylene to Ethylene in Excess Ethylene

Semi-hydrogenation of acetylene in excess ethylene is important in purifying alkene streams. Industrially used Pd-based catalysts are highly active but suffer from low selectivity. Supported Pd single-atom catalysts (SACs) are promising in this reaction but the fabrication of highly stable Pd SACs remains a grand challenge. In this work, we have developed a stable MgO supported Pd SAC by ball-milling method which showed good catalytic performance. The strong interaction between Pd atoms and MgO support not only inhibited the aggregation of Pd atoms, but also resulted in a high chemical state of Pd which may facilitate the adsorption as well as reactivity of acetylene. In addition, the isolation nature of the SAC is in favour of ethylene desorption, giving rise to a high selectivity. This work provided a good example to develop highly stable Pd SAC for catalytic semi-hydrogenation reaction with high efficiency.