Internal dry reforming of methane with carbon dixoide over Ni-based electrode in solid oxide membrane reactor

摘要

The dry reforming of methance with carbon dioxide has been studies over a Ni-based electrode-catalyst in a solid oxide membrane reactor under open-and closed-circult conditions. The effects of oxygen flux, reaction temperature, and feed concentration of performance of dry reforming of methance with carbon dioxide reaction have been investigated. Experiments were conducted using a solid oxide electrochemical membrane reactor consisting of an yittria stabilized zirconia (YSZ) disk as solid electrolyte with thin films of Ni-YSZ as the anode and La0.79Sr-0.16Mn0.8Co0.2O3 as the cathode. Also experiments were conducted over temperature ranges of 700-900oC and carbon dioxide/methane ratios of 0.5-2. During the reaction on Ni-based catalyst under open circuit condition, carbonaceous deposition took place, and resulted in unexpected decreases of reaction rates. Under closed-circuit conditions, passing anodic current which is electrochemically pumping of oxygen to the Ni-based electrode catalst, resulted in increases of methane reforming reaction rates and changes of product distributions. These were a reversible effects. Also carbonaceous deposition on Ni-based electrode was suppressed by acidic oxygen ion species (O2-, O-, O2-etc) electrochemically pumpoed to the anode.