A Porous Pyrochlore Y2[Ru1.6Y0.4]O7–δ Electrocatalyst for Enhanced Performance towards the Oxygen Evolution Reaction in Acidic Media

• Published in: Angewandte Chemie Vol. 130; no. 42; pp. 14073 - 14077
• Main Authors: Kim, Jaemin, Shih, Pei‐Chieh, Qin, Yao, Al‐Bardan, Zaid, Sun, Cheng‐Jun, Yang, Hong
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 15-10-2018
• Subjects: Batteries; Cations; Chemical synthesis; Chemistry; Electrocatalysts; Electrochemistry; Electrolytic cells; Elektrokatalyse; Fuel cells; Fuel technology; Organic chemistry; Oxygen; Oxygen evolution reactions; Perchloric acid; Performance enhancement; Porous materials; Porous media; Poröse Metalloxide; Pyrochlor; Sauerstoffentwicklungsreaktion; Stability; Substitution reactions; Wasserspaltung; Yttrium
• ISSN: 0044-8249; 1521-3757
• DOI: 10.1002/ange.201808825

A robust porous structure is often needed for practical applications in electrochemical devices, such as fuel cells, batteries, and electrolyzers. While templating approach is useful for the preparation of porous materials in general, it is not effective for the synthesis of oxide‐based electrocatalysts owing to the chemical instability of disordered porous materials thus created. Now the synthesis of phase‐pure porous yttrium ruthenate pyrochlore oxide using an unconventional porogen of perchloric acid is presented. The lattice oxygen defects are formed by the mixed‐valence state of Ru4+/5+ through the partial substitution of Ru4+ with Y3+ cations, leading to the formation of mixed B‐site Y2[Ru1.6Y0.4]O7−δ. This porous Y2[Ru1.6Y0.4]O7−δ electrocatalyst exhibits a turnover frequency (TOF) of 560 s−1 (at 1.5 V versus RHE) for the oxygen evolution reaction, which is two orders of magnitude higher than that of the RuO2 reference catalyst (5.41 s−1).
Poröses Y2[Ru1.6Y0.4]O7−δ wurde mit Perchlorsäure als ungewöhnlichem Porenbildner synthetisiert. Der Pyrochlor zeigte eine exzellente Aktivität in der Sauerstoffentwicklungsreaktion (OER) in sauren Medien, mit einer Umsatzfrequenz (TOF) von 560 s−1 (bei 1.5 V gegen RHE) am Ru‐Zentrum. Eine große poröse Oberfläche und Sauerstoffdefekte (aufgrund der partiellen Substitution von Ru4+ mit Y3+) spielen eine wichtige Rolle für die erhöhte OER‐Aktivität.