Core-shell structured Pd catalyst layer encapsulated by polydopamine for a gas-liquid-solid microreactor

In this work, a core-shell structured palladium catalyst layer in a gas-liquid-solid microreactor was proposed for the catalytic nitrobenzene hydrogenation through a facile and efficient approach. Via encapsulating the active palladium cores with the polydopamine shell, the proposed structure can construct barriers between the neighboring nanoparticles to not only inhibit the particle migration and aggregation during the hydrogen reduction and catalytic reaction processes but also protect the active palladium cores from being leaching. Because of these merits, the proposed core-shell structured palladium catalyst layer can significantly intensify the catalysis performance. Experimental results indicated that the developed catalyst layer showed good catalytic activity and operation durability. Compared to the conventional catalyst layer, the core-shell structure exhibited a 120% improvement in terms of the durability. Besides, the effect of the polydopamine encapsulating time on the structure and catalysis performance was also investigated. The best performance was achieved with the encapsulating time of 4 h in the present work. The obtained results reveal a facile and efficient avenue for designing the high-performance microreactors.