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

Abstract Herein, an effective top‐down etching route is presented to in situ fabricate CuO/CeO 2 nanohybrids on the surface of Cu 2 O 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 Cu 2 O cubes. After etched by aid of ammonia and Ce 3+ ions the final products are in a well‐defined spiny yolk@shell structures, in which the unetched part of Cu 2 O cubes serves as the core and the shell is composed by the CuO nanothorns encapsulated by CeO 2 nanoparticles. Systematical characterizations including scanning electron microscopy, transmission electron microscopy, X‐ray diffraction, X‐ray photoelectron spectroscopy, H 2 ‐temperature programmed reduction, N 2 sorption, firmly disclose the relationship between the catalytic properties and the structures of samples. By simply tuning the usage amount of ammonia and Ce 3+ ions, the samples show a typical volcano curve in the model reaction of catalytic CO oxidation. Sample CuO@CeO 2 ‐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.