Precise Synthesis of Hollow Mesoporous Palladium–Sulfur Alloy Nanoparticles for Selective Catalytic Hydrogenation

Hollow mesoporous metals have unique potential for catalysis, but their precise synthesis and further elaboration of their structure–performance relationships are still huge challenges. Herein, we report a new synthetic strategy, named the Kirkendall effect in synergistic template (KEST), for the desired preparation of hollow mesoporous palladium–sulfur (h-mesoPdS) alloy nanoparticles. The KEST strategy combines the Kirkendall cavitation synthesis of hollow PdS alloys at the atomic level and the nanocasting growth of a highly ordered mesoporous framework at the mesoscopic level, resulting in one-step solid-phase synthesis of binary h-mesoPdS alloy nanoparticles under ambient conditions. The h-mesoPdS possesses hollow and mesoporous geometry as well as binary PdS alloy composition, which synergistically optimize their electronic structures and energetically adjust the hydrogenation reaction trends. The h-mesoPdS alloy nanoparticles show a remarkable selectivity of 94% for semi-hydrogenating 4-nitrophenylacetylene to industrially important 4-nitrostyrene without hydrogenating the nitro group or over-hydrogenating the alkynyl group. Because of the significant advances in both synthesis and catalysis, this work paves a new route for realizing the targeted synthesis of highly efficient nanomaterials in various applications.