Core–Shell Structuring of Pure Metallic Aerogels towards Highly Efficient Platinum Utilization for the Oxygen Reduction Reaction

• Published in: Angewandte Chemie (International ed.) Vol. 57; no. 11; pp. 2963 - 2966
• Main Authors: Cai, Bin, Hübner, René, Sasaki, Kotaro, Zhang, Yuanzhe, Su, Dong, Ziegler, Christoph, Vukmirovic, Miomir B., Rellinghaus, Bernd, Adzic, Radoslav R., Eychmüller, Alexander
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 05-03-2018; Wiley
• Edition: International ed. in English
• Subjects: Aerogels; Chemical reduction; core–shell structures; electrocatalysis; Electrocatalysts; INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; Oxygen; oxygen reduction reaction; Oxygen reduction reactions; Palladium base alloys; Platinum; sol–gel processes; Substrates; Volcanoes; core-shell structures; aerogels; oxygen reduction reaction; electrocatalysis; sol-gel processes
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201710997

The development of core–shell structures remains a fundamental challenge for pure metallic aerogels. Here we report the synthesis of PdxAu‐Pt core–shell aerogels composed of an ultrathin Pt shell and a composition‐tunable PdxAu alloy core. The universality of this strategy ensures the extension of core compositions to Pd transition‐metal alloys. The core–shell aerogels exhibited largely improved Pt utilization efficiencies for the oxygen reduction reaction and their activities show a volcano‐type relationship as a function of the lattice parameter of the core substrate. The maximum mass and specific activities are 5.25 A mgPt−1 and 2.53 mA cm−2, which are 18.7 and 4.1 times higher than those of Pt/C, respectively, demonstrating the superiority of the core–shell metallic aerogels. The proposed core‐based activity descriptor provides a new possible strategy for the design of future core–shell electrocatalysts.
Core–shell nanocatalysts: A universal strategy was developed for the synthesis of core–shell structured pure metallic aerogels with a Pd‐based core and ultrathin Pt shell. The aerogels showed a largely improved Pt utilization efficiency for the oxygen reduction.