Effects of Praseodymium doping to oxygen reduction activity on Nd2-xPrxNiO4+d cathode

JESUS VEGA CASTILLO; ALBERTO CANEIRO; ALEJANDRA MONTENEGRO HERNÁNDEZ; LILIANA MOGNI

PyeongChang

Conferencia; the 22nd International Conference on Solid State Ionics(SSI-22); 2019

Korean Ceramic Society

Ln2NiO4+d oxides with K2NiF4-type structure are considered to be some of the most attractive electrodes for Solid oxide fuel cells (SOFC) application [1], they have lowthermal expansion coefficient values and high surface exchange and oxygen diffusion coefficients. Their crystal structure consists of LnNiO3 perovskite layers stackedalternating with rock salt LnO layers. Some authors have reported a promising performance of Ln2NiO4+d (Ln: La, Pr and Nd) as oxygen reduction electrodes, especially forLn=Pr [2]. Nevertheless, other studies show that Pr2NiO4+d (PNO) is not thermally stable at temperatures below 900 ºC and tends to segregate secondary phases thatharm its electrochemical properties [3]. Nd2NiO4+d (NNO) instead, shows thermal stability and chemical compatibility with a few electrolyte materials, below 900 ºC [4].Aiming to combine the good electrochemical features of PNO with the thermal stability and chemical compatibility of NNO, solid solutions between PNO and NNO suchas Nd2-xPrxNiO4+d (NPNO, x=0.3, 1 and 1.7) were studied. NPNO are prepared successfully by HMTA method. The effects of praseodymium doping on the crystal structure,the oxygen non-stoichiometry, and the cathode properties are evaluated by XRD, SEM, DTA, TGA and EIS.