CH4 internal dry reforming over a Ni/YSZ/ScSZ anode catalyst in a SOFC: A transient kinetic study

• Published in: Catalysis communications 2017-12, Vol.102 (C), p.62-66
• Main Authors: Yin, Wenbin, Chuang, Steven S.C.
• Format: Article
• Language: English
• Subjects: Carbon deposition; Chemistry; Dry reforming; Electrochemical oxidization; INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Ni/YSZ/ScSZ; SOFC; Transient response
• ISSN: 1566-7367; 1873-3905
• DOI: 10.1016/j.catcom.2017.08.027

We used a transient kinetic technique, which involves a step-switching of the reactant flows, to identify the reaction pathways on the Ni anode catalysts of SOFCs utilizing CH4/CO2 and CH4 as fuels. Carbon deposited at the external layer of the Ni anode support in CH4-SOFC. The transient response revealed that carbon deposition, which occurred with CH4 as a fuel molecule, was suppressed and dominated by the dry reforming of CH4/CO2 to CO/H2 and the electrochemical oxidization of CO/H2. Electricity generation from the electrochemical oxidation reactions is governed by Faraday resistance at the anode Ni catalyst interlayer. [Display omitted] •CH4-SOFC produced electricity by 2Hads+O2–→H2O+2e− and Cads+O2–→CO+2e−.•CO2 inhibited carbon deposition on the Ni/YSZ/ScSZ anode.•The reactivity for oxidization decreased in the order: Hads>COads>Cads.amorph>Cads.graph.•CH4/CO2-SOFC can be improved by promoting COads+O2–→CO2+2e− on the Ni anode catalyst interlayer.