Ammonia sensors based on stabilized zirconia and CoWO4 sensing electrode

Abstract A series of tungstate MWO 4 (M = Co, Zn and Ni) has been prepared by the polymeric precursor method. Meanwhile, yttria stabilized-zirconia (YSZ) based sensors using these oxides as sensing electrodes were investigated, and among the oxides tested, CoWO 4 was found to be the most suitable for the sensing electrode (SE) of the ammonia sensor. The sensor attached with CoWO 4 shows the fast response and recovery characteristics (not more than 5 s respectively) and large sensitivity (− 51 mV/decade) at elevated temperature. The electric potential difference (∆V) of the sensor varies almost linearly with the NH 3 concentrations in the examined range of 50–1000 ppm. The SEM observation reveals that the special microstructure of CoWO 4 -SE, bulky rod-like crystals coated by tiny particles, plays a significant role in sensing performance.

[1]  Ralf Moos,et al.  Development and working principle of an ammonia gas sensor based on a refined model for solvate supported proton transport in zeolites , 2003 .

[2]  Weimin Du,et al.  Preparation and gas sensing properties of ZnM2O4 (M = Fe, Co, Cr) , 2004 .

[3]  K. Kondo,et al.  Proton-Conducting Thin Film Grown on Yttria-Stabilized Zirconia Surface for Ammonia Gas Sensing Technologies , 2009 .

[4]  Y. Shimizu,et al.  Desorption behavior of ammonia from TiO2-based specimens — ammonia sensing mechanism of double-layer sensors with TiO2-based catalyst layers , 2000 .

[5]  Ralf Moos,et al.  Selective ammonia exhaust gas sensor for automotive applications , 2002 .

[6]  R. Burch,et al.  Knowledge and Know‐How in Emission Control for Mobile Applications , 2004 .

[7]  Norio Miura,et al.  Stabilized Zirconia-Based Sensor Attached with NiO ∕ Au Sensing Electrode Aiming for Highly Selective Detection of Ammonia in Automobile Exhausts , 2008 .

[8]  P. Gouma,et al.  Comparison of sol–gel and ion beam deposited MoO3 thin film gas sensors for selective ammonia detection , 2003 .

[9]  Matsumoto Shinichi,et al.  Recent advances in automobile exhaust catalysts , 2004 .

[10]  C. Li,et al.  Surface Treatment and Doping Dependence of In2O3 Nanowires as Ammonia Sensors , 2003 .

[11]  M. Ivanovskaya,et al.  A study of sensing properties of Pt- and Au-loaded In2O3 ceramics , 1999 .

[12]  Chao-Nan Xu,et al.  Selective detection of NH3 over NO in combustion exhausts by using Au and MoO3 doubly promoted WO3 element , 2000 .

[13]  K. Vijayamohanan,et al.  A highly selective ammonia gas sensor using surface-ruthenated zinc oxide , 1999 .

[14]  Gunter Hagen,et al.  Zeolite-based Impedimetric Gas Sensor Device in Low-cost Technology for Hydrocarbon Gas Detection , 2008, Sensors.

[15]  Tong Zhang,et al.  Surface state studies of TiO2 nanoparticles and photocatalytic degradation of methyl orange in aqueous TiO2 dispersions , 2001 .

[16]  Mana Sriyudthsak,et al.  Methanol and ammonia sensing characteristics of sol–gel derived thin film gas sensor , 2000 .

[17]  Kenichi Shimizu,et al.  Effects of Calcination Temperature and Acid-Base Properties on Mixed Potential Ammonia Sensors Modified by Metal Oxides , 2011, Sensors.

[18]  K. Shimizu,et al.  Doped-vanadium oxides as sensing materials for high temperature operative selective ammonia gas sensors , 2009 .

[19]  E. Obermeier,et al.  Sputtered molybdenum oxide thin films for NH3 detection , 1996 .

[20]  Kari Eränen,et al.  Toward improved catalytic low-temperature NOx removal in diesel-powered vehicles. , 2006, Accounts of chemical research.

[21]  Maximilian Fleischer,et al.  Selective Mixed Potential Ammonia Exhaust Gas Sensor , 2009 .

[22]  E. Llobet,et al.  A route toward more selective and less humidity sensitive screen-printed SnO2 and WO3 gas sensitive layers , 2004 .

[23]  M. Hirata,et al.  Research into normal temperature gas-sensitive characteristics of polyaniline material , 1993 .

[24]  Jin Ho Kim,et al.  Fabrication of nanoporous and hetero structure thin film via a layer-by-layer self assembly method for a gas sensor , 2004 .

[25]  M. Elsener,et al.  Urea-SCR: a promising technique to reduce NOx emissions from automotive diesel engines , 2000 .

[26]  Haibo Pan,et al.  Selectivity of Ti-doped In2O3 ceramics as an ammonia sensor , 2006 .