Half-cell potentials of the electrochemical cell Au, VWT | YSZ | Au are analyzed in dependence on oxygen and ammonia concentration at 550 °C. One of the gold electrodes is covered with a porous SCR catalyst, vanadia-tungstenia-titania (VWT). The cell is utilized as a potentiometric ammonia gas sensor and provides a semi-logarithmic characteristic curve with a high NH3 sensitivity and selectivit...

In this study, small fraction of NiTi (5 wt%) was added to Yttria stabilized zirconia (YSZ) top coat to improve it sliding wear resistance. The measurement of width of wear tracks after wear tests under a 15 N load for 100 m sliding distances showed that the width of wear track in NiTi-YSZ coating is shorter than that in YSZ coating which depicts the higher wear resistance of NiTi-YSZ coa...

As the pursuit towards emissions reduction intensifies with growing interest and nascent technologies, solid oxide fuel cells (SOFCs) remain an illustrious candidate for achieving our goals. Despite myriad advantages, SOFCs are still too costly for widespread deployment, even as unprecedented materials developments have recently emerged. This suggests that, in addition to informed materials sel...

Using impedance spectroscopy the electrical response of sensors with various porous Y-stabilized ZrO2 (YSZ) microstructures was measured for gas concentrations containing 0-100 ppm NO with 10.5%O2 at temperatures ranging from 600-700 °C. The impedance response increased substantially as the sensor porosity increased from 46%-50%. Activation energies calculated based on data from the impedance m...

Introduction: The direct use of CH4 as the feed to the solid oxide fuel cell (SOFC) will allow elimination of a reformer, simplifying the SOFC system and decreasing the system cost [1]. The overall reaction on the anode catalyst in the direct CH4 SOFC is the electrochemical oxidation of CH4: CH4 + 4O CO2 + 2H2O + 8e. Due to the nature of hydrocarbon reactions at high temperature and the reducin...

Unraveling structural dynamics of noble metal nanoclusters on oxide supports is critical to understanding reaction process and origin of catalytic activity in heterogeneous catalysts. Here, we show that aberration-corrected scanning transmission electron microscopy can provide direct atomic-resolution imaging of surface migration, coalescence, and atomic rearrangement of Au clusters on an Y:ZrO...

We report a Ni-Cr/C electrocatalyst with unprecedented mass-activity for the hydrogen evolution reaction (HER) in alkaline electrolyte. The HER kinetics of numerous binary and ternary Ni-alloys and composite Ni/metal-oxide/C samples were evaluated in aqueous 0.1 M KOH electrolyte. The highest HER mass-activity was observed for Ni-Cr materials which exhibit metallic Ni as well as NiO x and Cr2O3...