The effects of Cu-content on Mg₂Cu_xFe₁O_3.5+x electrodes for YSZ-based mixed-potential type NH₃ sensors

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• 作者：Xiangdong Li ; Chao Wang ; Jinqiang Huang ; Yu Yuan ; Bing Wang ; Haibo Zhang ; Feng Xia ; Jianzhong Xiao ; ^{jzxiao@mail.hust.edu.cn" class="auth_mail" title="E-mail the corresponding author}
• 关键词：NH3 sensor ; YSZ ; Mixed-potential type ; Mg2CuxFe1O3.5+x ; SCO catalyst materials
• 刊名：Ceramics International
• 出版年：2016
• 出版时间：June 2016
• 年：2016
• 卷：42
• 期：8
• 页码：9363-9370
• 全文大小：8180 K

文摘

Yttria-stablized zirconia (YSZ)-based mixed-potential type NH₃ sensors using Mg₂Cu_xFe₁O_3.5+x mixed metal oxides (x=0, 0.25, 0.50, 1) as sensing electrode material were fabricated for ammonia (NH₃) detection at different working temperatures (T=350 °C, 400 °C, 450 °C, 500 °C). The Mg₂Cu_xFe₁O_3.5+x electrodes were characterized by X-Ray Diffraction (XRD), Environmental Scanning Electron Microscope (ESEM), Energy Dispersive Spectrometer (EDS) and the Brunauer–Emmett–Teller (BET) method. The effects of Cu-content on phase composition, microstructures, NH₃ response performances and electrochemically catalytic-activity of Mg₂Cu_xFe₁O_3.5+x electrodes were discussed. Magnesium copper oxide (Mg_0.78Cu_0.22O) may be a functional phase that improved NH₃ sensitivity of Mg₂Cu_xFe₁O_3.5+x electrodes, but magnesium dicopper oxide (Cu₂MgO₃) played an opposite role as a suppressive phase. The Mg₂Cu_0.25Fe₁O_3.75 electrode exhibits the biggest response (about 267 mV for 200 ppm of NH₃), the highest NH₃ sensitivity (220 mV/decade NH₃) and the highest electrochemically catalytic-activity may be attributed to its suitable Cu-content for functional phase (Mg_0.78Cu_0.22O) with higher NH₃ adsorptivity, which can absorb more NH₃ to the triple-phase boundary (TPB) for the electrochemically reaction.