Effect of H₂S and HCl contaminants on nickel and ceria pattern anode solid oxide fuel cells

In this study, with the motivation of elucidating the effect of H₂S and HCl on solid oxide fuel cell anodes, nickel and ceria pattern anodes are prepared on yttrium-stabilized zirconia electrolyte, and the effect of H₂S and HCl on their performance is tested using electrochemical impedance spectroscopy. However, it has...

Adverse effects of potassium on NO_x reduction over Di-Air catalyst (Rh/La-Ce-Zr)

The influence of potassium in Rh on a lanthium promoted zirconia stablised ceria (CZ) catalysts was studied toward NO_xreduction reactivity and selectivity. The results are compared with a Rh/CZ catalyst. The samples were characterised by N₂ adsorption, XRD, SEM, ICP, and H₂-TPR. The study highlighted the...

NO_x reduction in the Di-Air system over noble metal promoted ceria

In this study, the role of the noble metals Pt and Rh (0.5 wt.%) for the selective reduction of NO into N₂ is evaluated by the transient TAP technique and in-situ spectroscopy using a commercial stable ceria support (denoted as CZ) and applying isotopically labelled ¹⁵NO and ¹⁸O₂. The transient...

Fundamental understanding of the Di-Air system (an alternative NO_x abatement technology). I: The difference in reductant pre-treatment of ceria

Toyota's Di-Air DeNO_x system is a promising DeNO_x system to meet NO_x emission requirement during the real driving, yet, a fundamental understanding largely lacks, e.g. the benefit of fast frequency fuel injection. Ceria is the main ingredient in Di-Air catalyst composition. Hence, we investigated the reduction...

The influence of CO₂ on NO reduction into N₂ over reduced ceria-based catalyst

Oxygen defects in reduced ceria are the catalytic sites for the NO reduction into N₂ in the Toyota Di-Air DeNO_x abatement technology. Traces of NO (several hundred ppm) have to compete with the excess amount of other oxidants, e.g., 5% CO₂ and 5% O₂, in an exhaust gas of a lean burn (diesel) engine....

A detailed look into hydrogen electrochemical oxidation on ceria anodes

Using the Nernst-Planck-Poisson model and a detailed reaction mechanism, we studied the hydrogen electrochemical oxidation on a ceria anode. Resistances caused by surface kinetics, and bulk transport of oxide-ion vacancies and electrons are computed individually to identify the dominant resistive process. The effect of operating conditions...

Next Generation Automotive DeNO_X Catalysts: Ceria What Else?

Nitrogenoxides (NOx, including NO and NOx) are a group of hazardous, toxic and harmfulgasses, which have an adverse effect on both environment and human health,e.g., acid rain, photochemical smog, and affecting the human respiratorysystem. The NOx concentration in most of the EUcities exceeds the EU annual limit value (40 μg/m3). Around40% of...

Electrochemical oxidation of syngas on nickel and ceria anodes

Fuel flexibility of solid oxide fuel cells enables the use of low cost and practical fuels like syngas. Understanding of the oxidation kinetics with syngas is essential for proper selection of anode material and its design optimization. Using nickel and ceria pattern anodes, we study the electrochemical oxidation of syngas in both dry and wet...

Contact dynamics for a solid-solid reaction mediated by gas-phase oxygen: Study on the soot oxidation over ceria-based catalysts

Ceria-based catalysts with different topological and textural properties have been prepared to study the role of the soot-catalyst contact on the soot oxidation reaction. The physico-chemical features of the catalysts have been investigated by means of complementary techniques, such as powder XRD, N₂ physisorption at -196 °C,...

Fundamental Understanding of the Di-Air System: The Role of Ceria in NO_x Abatement

Temporal analysis of product (TAP) is used to investigate the effectiveness of CO, C₃H₆, and C₃H₈ in the reduction of a La–Zr doped ceria catalyst and NO reduction into N₂ over this pre-reduced catalyst. Hydrocarbons are found to be substantially more effective in the reduction of this...