Design of Anode Materials for IT SOFC:Effect of Complex Oxide Promoters and Pt Group Metals on Activity and Stability in Methane Steam Reforming of Ni/YSZ (ScSZ) Cermets

Ni/YSZ or Ni/ScCeSZ cermets were promoted by up to 10 wt % of fluoritelike (Pr-Ce-Zr- O, La-Ce-Zr-O, and Ce-Zr-O) or perovskitelike (La-Pr-Mn-Cr-O) oxides and small (up to 1.4 wt %) amounts of Pt group metals (Pd, Pt, or Ru). Reactivity of samples, their lattice oxygen mobility, and their ability to activate methane were characterized by temperature-programed reduction by CH4. The catalytic properties of these samples in methane steam reforming were studied at 500-850 degrees C and short contact times (10 ms) in feeds with 8 mol % of CH4 and steam/methane ratio of 1: 3. Oxide promoters ensure stable performance of cermets in stoichiometric feeds at T &gt; 650 degrees C by suppressing carbon deposition. Copromotion with precious metals enhances performance in the intermediate temperature (450-600 degrees C) range due to more efficient activation of methane. Factors determining specificity of these cermet materials' performance (chemical composition, microstructure, oxygen mobility in oxides, interaction between components, and reaction media effect) are considered. The most promising systems for practical application are Pt/Pr-Ce-Zr-O/Ni/YSZ and Ru/La-Pr-Mn-Cr-O/Ni/YSZ cermets demonstrating a high performance in the intermediate temperature range under broad variation in steam/CH4 ratio. [DOI: 10.1115/1.3117255]</p

Design of Anode Materials for IT SOFC: Effect of Complex Oxide Promoters and Pt Group Metals on Activity and Stability in Methane Steam Reforming of Ni/YSZ &quot;ScSZ… Cermets

small (up to 1.4 wt %) amounts of Pt group metal

Design of anodes for IT SOFC: Effect of complex oxide promoters and pd on activity and stability in methane steam reforming of Ni/YSZ (ScSZ) cermets

Effect of fluorite-like or perovskite-like complex oxide promoters and Pd on the performance of Ni/8YSZ and Ni/ScSZ anode materials in CH4 steam reforming (SR) or selective oxidation (SO) by O-2 into syngas was studied. The spatial uniformity of dopants distribution in composites was controlled by TEM combined with EDX analysis, while the lattice oxygen mobility and reactivity were estimated by CH4 and H-2 temperature-programmed reduction (TPR). The oxide promoters suppress the coke deposition even at stoichiometric H2O/CH4 ratio, while doping by Pd ensures a good performance at moderate (similar to 550 degrees C) temperatures required for the Intermediate -Temperature Solid Oxide Fuel Cells (IT SOFC) operation.</p

Design of anodes for IT SOFC: Effect of complex oxide promoters and pd on activity and stability in methane steam reforming of Ni/YSZ (ScSZ) cermets

Effect of fluorite-like or perovskite-like complex oxide promoters and Pd on the performance of Ni/8YSZ and Ni/ScSZ anode materials in CH4 steam reforming (SR) or selective oxidation (SO) by O-2 into syngas was studied. The spatial uniformity of dopants distribution in composites was controlled by TEM combined with EDX analysis, while the lattice oxygen mobility and reactivity were estimated by CH4 and H-2 temperature-programmed reduction (TPR). The oxide promoters suppress the coke deposition even at stoichiometric H2O/CH4 ratio, while doping by Pd ensures a good performance at moderate (similar to 550 degrees C) temperatures required for the Intermediate -Temperature Solid Oxide Fuel Cells (IT SOFC) operation.</p