A Controllable Surface Etching Strategy for Well‐Defined Spiny Yolk@Shell CuO@CeO2 Cubes and Their Catalytic Performance Boost.

Herein, an effective top‐down etching route is presented to in situ fabricate CuO/CeO2 nanohybrids on the surface of Cu2O microcube templates. This method has well taken into account the factors both in thermodynamics and in kinetics, including surface structural nanocrystallization, construction of mesopores, formation of stable core@shell structures, and strengthened synergistic effects, in order to realize the structural design and hence greatly improve catalytic performance caused by surface nanocrystallization of Cu2O cubes. After etched by aid of ammonia and Ce3+ ions the final products are in a well‐defined spiny yolk@shell structures, in which the unetched part of Cu2O cubes serves as the core and the shell is composed by the CuO nanothorns encapsulated by CeO2 nanoparticles. Systematical characterizations including scanning electron microscopy, transmission electron microscopy, X‐ray diffraction, X‐ray photoelectron spectroscopy, H2‐temperature programmed reduction, N2 sorption, firmly disclose the relationship between the catalytic properties and the structures of samples. By simply tuning the usage amount of ammonia and Ce3+ ions, the samples show a typical volcano curve in the model reaction of catalytic CO oxidation. Sample CuO@CeO2‐0.05 exhibits the optimal catalytic activity and stability. It is believed that this top‐down strategy has shown promising future to design high‐performance catalysts for the practical need of application. An effective top‐down route is presented to in situ fabricate CuO/CeO2 nanohybrids on the surface of Cu2O microcube templates. After etched by aid of ammonia and Ce3+ ions the products are in well‐defined spiny yolk@shell structures, which show excellent catalytic performance on catalytic CO oxidation. [ABSTRACT FROM AUTHOR]