Details

Autor(en) / Beteiligte

• Kim, Nam-In
• Cho, Sung-Hwa
• Park, Se Hwan
• Lee, Young Joo
• Afzal, Rana Arslan
• Yoo, Jeseung
• Seo, Young-Soo
• Lee, Yun Jung
• Park, Jun-Young

Titel

B-site doping effects of NdBa0.75Ca0.25Co2O5+δ double perovskite catalysts for oxygen evolution and reduction reactionsElectronic supplementary information (ESI) available. See DOI: 10.1039/c8ta06236f

Erscheinungsjahr

2018-09

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• As bifunctional electrocatalysts for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), we introduce an economical, particularly active, stable, and completely noble-metal-free catalyst based on CaO-doped NdBaCo 2 O 5+ δ with the aim of exploiting its high catalytic activity for the oxygen electrode. Further, the electrochemical performances of the NdBa 0.75 Ca 0.25 Co 2 O 5+ δ catalyst are improved by doping transition-metal oxides (Fe 2+ , Ni 2+ , Cu 2+ , and Mn 2+ ) into the B-sites of double perovskite oxides, facilitating the movement of electrons and oxygen-ions through oxygen vacancies. Among these, NdBa 0.75 Ca 0.25 Co 1.5 Fe 0.5 O 5+ δ (NBCCFe) shows the highest electrocatalytic oxygen electrode activity for the OER and ORR, and NBCCFe thus is hybridized with nitrogen-reduced graphene oxide (N-rGO) to further improve its catalytic activity with excellent durability. Hybridization of NBCCFe with N-rGO further boosts bifunctional oxygen electrode activity (0.761 V) with better durability, which surpasses those of Pt/C (0.815 V) and Ir/C (0.768 V) catalysts. A rechargeable lithium-air battery assembled with the NBCCFe/N-rGO catalyst exhibits remarkably improved discharge capacity, reduced charge overpotential and an extended cycle life, corroborating the excellent bifunctional catalytic activity of NBCCFe/N-rGO. The NBCCFe/N-rGO catalyst also displays the most improved polarization during both discharge and charge, further confirming the highest bifunctional catalytic activity of NBCCFe/N-rGO. NdBa 0.75 Ca 0.25 Co 2 O 5+ δ -based double perovskite catalysts provide new ways for significantly enhanced oxygen-related electrochemical reactions with durable characteristics in alkaline atmospheres.