Performance of Ni/10Sc1CeSZ anode synthesized by glycine nitrate process assisted by microwave heating in a solid oxide fuel cell fueled with hydrogen or methane

Abstract

Nickel/scandia-ceria-stabilized-zirconia (Ni/10Sc1CeSZ) cermet is a potential anode for solid oxide fuel cells. The anode powder is prepared through a microwave-assisted glycine nitrate combustion process, and its properties, including phase and chemical composition as well as morphology, are characterized by XRD, TEM, and EDS techniques. The electrical conductivity and electrochemical behavior under low concentration of dry hydrogen (H2:N2 volume ratio = 10:90) and dry methane (CH4:N2 volume ratio = 50:50) fuels are determined. XRD results show two phases, namely, cubic NiO phase and cubic 10Sc1CeSZ phase, with the crystallite sizes of 67 and 40 nm, respectively. The area specific resistances (ASRs) of the prepared anode measured using a symmetrical cell of Ni/10Sc1CeSZ|10Sc1CeSZ|Ni/10Sc1CeSZ are 0.96 and 24.3 Ω cm2 observed at 800 °C in dry low hydrogen concentration (10 vol% hydrogen–90 vol% nitrogen) and dry methane (50 vol% methane–50 vol% nitrogen) fuels, respectively. The ASR in methane fuel is higher than that in hydrogen fuel at all operating temperatures (600–800 °C) because of carbon deposition. The amount of deposited carbon and degree of graphitization (IG/ID) of this anode after exposure in methane at 800 °C for 3 h are 4.34% and 2.1, respectively. Overall, Ni/10Sc1CeSZ cermet synthesized by glycine nitrate process assisted with microwave-heating technique exhibits acceptable electrochemical behavior even at low hydrogen concentration and also in dry methane. This can be related to the improved powder morphology as a result of uniform heating assisted by microwave energy.