Au-Pd core-shell nanoparticles for enhanced catalytic performance in liquid-phase selective hydrogenation.

Au-Pd core-shell nanoparticles are promising selective hydrogenation catalysts and can exhibit strongly enhanced catalytic activities compared to their alloyed and monometallic counterparts, while retaining high selectivity. However, little is known about their performance and structural stability during liquid-phase selective hydrogenation. Here, we test colloidally synthesized Au-Pd core-shell and alloyed nanoparticles for the selective hydrogenation of 2-methyl-3-butyn-2-ol to 2-methyl-3-buten-2-ol, a model reaction for selective hydrogenation of alkynols to alkenols used in vitamin and fragrance synthesis. The core-shell nanoparticles were significantly more active than their alloy counterparts and also more selective. Moreover, they also outperformed their Au and Pd monometallic counterparts, with the core-shell nanoparticles being ∼3.5× more active than monometallic Pd while retaining its selectivity. This work shows how the use of structure-controlled colloidal core-shell nanoparticles can be useful to enhance the performance in liquid-phase selective hydrogenation catalysis.