Nd-Doped Barium Cerate Nano-Sized Catalyst Converts CH4 into CO2 at Lower Temperature Compared to Noble Metal-Based Pd/Al2O3 Catalyst

The present paper describes the synthesis and first application of Nd-doped BaCeO3 nanoparticles as catalyst for the catalytic oxidation of methane (CH4) into CO2. Nd-doped barium cerate BaCeO3 nanoparticles, with the formula BaNdxCe(1-x)O3, have been prepared using a simple sol gel method starting from acetate precursors. The as-prepared nanoparticles have been fully characterized by XRD, TEM, HRTEM and specific surface area measurement. Results confirmed the formation of highly crystallized nano-sized particles with small crystallite size. In-situ FTIR spectroscopy was used to study the catalytic conversion of methane (CH4) into CO2 in the presence of the as-prepared Nd-doped BaCeO3 nanocatalyst. The catalytic properties of such nanocatalysts have been discussed and correlated to Nd-doping rate, crystallite diameter, and specific surface area of the materials. Excellent catalytic properties have been obtained with BaNd0.05Ce0.95O3, such as, superior conversion efficiency, longer catalysis lifetime and lower activation temperature compared to un-doped BaCeO3 catalyst. Interestingly, it was found that BaNd0.05Ce0.95O3 nanocatalyst successfully converts the totality of CH4 present in a mixture of CH4-Air into CO2 at much lower temperature compared to the conventional Pd/Al2O3 catalyst.

Analysis of the Electrochemical Transport Properties of Doped Barium Cerate for Proton Conductivity in Low Humidity Conditions: A Review

Proton-conducting perovskites are among the most promising electrolytes for Proton Ceramic Fuel Cells (PCFCs), electrolysers and separation membranes. Particularly, yttrium-doped barium cerate, BaCe1-xYxO3-δ (BCY), shows one of the highest protonic conductivities at intermediate temperatures (σ ∼ 10−3 S cm−1 at 400°C); values that are typically achieved under humidified atmospheres (p H2O ∼ 10−2 atm). However, BCY has commonly been discarded for such applications due to its instability in the presence of water vapour and carbonaceous atmospheres. A recent discovery has shown that BCY10 exhibits pure protonic conductivity under very low humidity contents (∼10−5–10−4 atm), owing to its very high equilibrium constant for hydration. This peculiar characteristic allows this material to retain its functionally as a proton conductor in such conditions, while preventing its decomposition. Hence, this chapter explores the electrochemical properties of the BaCe0.9Y0.1O3-δ (BCY10) composition, comprehensively establishing its limiting operation conditions through defect chemistry and thermodynamic analyses. Moreover, the importance of such conditions is highlighted with respect to potential industrially relevant hydrogenation/de-hydrogenation reactions at low temperatures under low humidity.

Protonated state and synergistic role of Nd3+ doped barium cerate perovskite for the enhancement of ionic pathways in novel sulfonated polyethersulfone for H2/O2 fuel cells

1.8 times higher current density and power density were obtained for a Nd3+ doped barium cerate membrane compared to pure SPES.

Preparation, Characterization and Intermediate-Temperature Electrochemical Properties of Er3+-Doped Barium Cerate–Sulphate Composite Electrolyte

In this study, BaCe0.9Er0.1O3−α was synthesized by a microemulsion method. Then, a BaCe0.9Er0.1O3−α–K2SO4–BaSO4 composite electrolyte was obtained by compounding it with a K2SO4–Li2SO4 solid solution. BaCe0.9Er0.1O3−α and BaCe0.9Er0.1O3−α–K2SO4–BaSO4 were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Raman spectrometry. AC impedance spectroscopy was measured in a nitrogen atmosphere at 400–700 °C. The logσ~log (pO2) curves and fuel cell performances of BaCe0.9Er0.1O3−α and BaCe0.9Er0.1O3−α–K2SO4–BaSO4 were tested at 700 °C. The maximum output power density of BaCe0.9Er0.1O3−α–K2SO4–BaSO4 was 115.9 mW·cm−2 at 700 °C, which is ten times higher than that of BaCe0.9Er0.1O3−α.