Self-supported Pt–CoO networks combining high specific activity with high surface area for oxygen reduction

• Published in: Nature materials Vol. 20; no. 2; pp. 208 - 213
• Main Authors: Sievers, Gustav W., Jensen, Anders W., Quinson, Jonathan, Zana, Alessandro, Bizzotto, Francesco, Oezaslan, Mehtap, Dworzak, Alexandra, Kirkensgaard, Jacob J. K., Smitshuysen, Thomas E. L., Kadkhodazadeh, Shima, Juelsholt, Mikkel, Jensen, Kirsten M. Ø., Anklam, Kirsten, Wan, Hao, Schäfer, Jan, Čépe, Klára, Escudero-Escribano, María, Rossmeisl, Jan, Quade, Antje, Brüser, Volker, Arenz, Matthias
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.02.2021; Nature Publishing Group
• Subjects: 119/118; 140/146; 639/301/299; 639/301/357; 639/638/161/886; 639/638/161/893; 639/925/357; Biomaterials; Catalysts; Chemistry and Materials Science; Cobalt; Cobalt oxides; Condensed Matter Physics; Costs; Fuel cells; High temperature; Humidification; Kinetics; Mass transport; Materials Science; Nanotechnology; Networks; Optical and Electronic Materials; Oxygen; Oxygen reduction reactions; Platinum; Surface area
• ISSN: 1476-1122; 1476-4660
• DOI: 10.1038/s41563-020-0775-8

Several concepts for platinum-based catalysts for the oxygen reduction reaction (ORR) are presented that exceed the US Department of Energy targets for Pt-related ORR mass activity. Most concepts achieve their high ORR activity by increasing the Pt specific activity at the expense of a lower electrochemically active surface area (ECSA). In the potential region controlled by kinetics, such a lower ECSA is counterbalanced by the high specific activity. At higher overpotentials, however, which are often applied in real systems, a low ECSA leads to limitations in the reaction rate not by kinetics, but by mass transport. Here we report on self-supported platinum–cobalt oxide networks that combine a high specific activity with a high ECSA. The high ECSA is achieved by a platinum–cobalt oxide bone nanostructure that exhibits unprecedentedly high mass activity for self-supported ORR catalysts. This concept promises a stable fuel-cell operation at high temperature, high current density and low humidification. A high oxygen reduction reaction activity can usually be realized by increasing platinum specific activity at the expense of active surface area. Self-supported platinum–cobalt-oxide networks combining high activity and surface area now promise a stable fuel-cell operation.