Precisely-controlled synthesis of Au@Pd core-shell bimetallic catalyst via atomic layer deposition for selective oxidation of benzyl alcohol

In this study, we report a novel facile strategy for atomically-precise synthesis of supported Au@Pd core-shell bimetallic catalyst via atomic layer deposition (ALD). By choosing a proper deposition condition, we can selectively deposit Pd only on Au nanoparticle surface, but not on SiO2 support to exclusively form Au@Pd core-shell bimetallic nanoparticles, while avoiding monometallic nanoparticle formation; therein, the Pd shell thickness can be atomically precisely tuned by varying the number of Pd ALD cycles. In solvent-free oxidation of benzyl alcohol, the catalytic activities of the resulted Au@Pd/SiO2 core-shell bimetallic catalysts showed a clear volcano-like trend with the Pd shell thickness, reaching a maximum at a Pd shell thickness of 0.6-0.8 nm due to the optimized synergistic effect. More importantly, we believe this new strategy of precise synthesis of core-shell structured bimetallic catalyst using ALD can be general to other supported bimetallic catalysts for broad applications. (C) 2015 Elsevier Inc. All rights reserved.