Polymer-templated synthesis of hollow Pd–CeO 2 nanocomposite spheres and their catalytic activity and thermal stability

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Vol. 3; no. 46; pp. 23230 - 23239
• Main Authors: Du, Chenhao, Guo, Yun, Guo, Yanglong, Gong, Xue-qing, Lu, Guanzhong
• Format: Journal Article
• Language: English
• Published: 2015
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/C5TA05092H

Developing methods for the fabrication of active and thermally stable noble metal/metal oxide nanomaterials are very important for catalysis and material fields. Herein, we used a polymer-template synthesis approach to prepare hollow Pd–CeO 2 nanocomposite spheres (NCSs) with Pd nanoparticles evenly distributed inside the CeO 2 shell, in which the aggregation of Pd nanoparticles can be well inhibited with the help of the protection of CeO 2 nanocrystallites even after being calcined at 700 °C. The Pd nanoparticles are partially buried in the CeO 2 shell and the surface Pd species are highly ionic, which is caused by the electron exchange at the Pd–CeO 2 interface during calcination. This hollow structure Pd–CeO 2 nanocatalyst shows excellent catalytic activity and stability in the aqueous selective reduction of 4-nitrophenol and gaseous CO oxidation. For the selective reduction of 4-nitrophenol, the reaction rate of this h-Pd–CeO 2 NCS catalyst compared to those of the supported Pd/CeO 2 and physically mixed Pd + CeO 2 catalysts is almost 14 times and 5 times faster, respectively. For the CO oxidation, the larger Pd–CeO 2 interface in h-Pd–CeO 2 NCSs could facilitate the reaction between the adsorbed CO and O 2 , thus showing better low temperature activity. This paper emphasizes the advantages of a core–shell hollow structure and provides a new way for obtaining novel functional nanocatalysts.