Kumar Baral Ashok, Vijaya Sankar Kalimuthu, Matatyaho Asia, Kushnir Gil, Tsur Yoed
Department of Chemical Engineering, Technion- Israel Institute of Technology, Haifa, 3200003, Israel.
The Nancy and Stephen Grand Technion Energy Program, Technion- Israel Institute of Technology, Haifa, 3200003, Israel.
ChemSusChem. 2020 Nov 6;13(21):5671-5682. doi: 10.1002/cssc.202001503. Epub 2020 Sep 18.
Perovskite oxides are at the forefront of the race to develop catalysts/electrodes for fuel cells and electrolyzers. This work presents trifunctional properties of the double-perovskite oxide PrBa Sr Co Fe O and the PrBa Sr Co Fe O -Ag composite prepared by the glycine nitrate process. The electrocatalytic studies reveal that the Ag-based composite is an excellent catalyst for both oxygen evolution (OER) and hydrogen evolution reactions (HER) in alkaline solution. The electrochemical impedance spectroscopy analysis through distribution function of relaxation times (DFRT) suggests that the improved activity originates from the suppression of resistance contributed by various relaxation processes. The oxygen reduction reaction (ORR) kinetics in these oxide-based cathodes has been studied by performing symmetric-cell measurements at high temperatures using both oxygen-ion and proton-conducting cells. DC bias dependence of charge-transfer processes, oxygen-surface kinetics, polarization resistances, and activation energies are revealed by DFRT studies. Ag addition in PrBa Sr Co Fe O leads to enhanced kinetics of OER, HER, and ORR.
钙钛矿氧化物在开发用于燃料电池和电解槽的催化剂/电极的竞赛中处于前沿地位。这项工作展示了通过甘氨酸硝酸盐法制备的双钙钛矿氧化物PrBaSrCoFeO以及PrBaSrCoFeO-Ag复合材料的三功能特性。电催化研究表明，基于银的复合材料是碱性溶液中析氧反应（OER）和析氢反应（HER）的优良催化剂。通过弛豫时间分布函数（DFRT）进行的电化学阻抗谱分析表明，活性的提高源于对各种弛豫过程所贡献电阻的抑制。通过使用氧离子传导电池和质子传导电池在高温下进行对称电池测量，研究了这些基于氧化物的阴极中的氧还原反应（ORR）动力学。DFRT研究揭示了电荷转移过程、氧表面动力学、极化电阻和活化能的直流偏置依赖性。在PrBaSrCoFeO中添加银会导致OER、HER和ORR的动力学增强。
