The catalytic performance of Ni-containing limonite ore in the dry reforming reaction of methane （CH_4＋CO_2→2H_2＋2CO） was determined before and after hydrogen reduction, and under a flow of hydrogen. After hydrog...The catalytic performance of Ni-containing limonite ore in the dry reforming reaction of methane （CH_4＋CO_2→2H_2＋2CO） was determined before and after hydrogen reduction, and under a flow of hydrogen. After hydrogen reduction, the limonite ore exhibited higher catalytic performance, because of the formation of Fe-Ni. However, the Fe in Fe-Ni was readily oxidized by the input CO_2 gas. resulting in a rapid decrease in the catalytic performance of limonite ore. The performance de- crease was due to a decrease in the Ni surface area; Ni could not dissolve in iron oxides and this caused segregation in the iron oxides. When the reaction was conducted under a hydrogen flow, the Fe-Ni was formed and maintained. Ni was highly dispersed in the Fe-Ni phase, resulting in greater surface area of Ni and higher conversion rate of CH_4 and CO_2. The catalytic performance of the limonite ore was inferior to the Ni/Al_2O_3 catalyst because the effect of catalyst support was small, however, the limonite ore was more stable during catalytic use and much cheaper than the Ni/Al_2O_3.展开更多
基金supported by the Grant-in-Aid for Research Fellow of Japan Society for the Promotion of Science
文摘The catalytic performance of Ni-containing limonite ore in the dry reforming reaction of methane （CH_4＋CO_2→2H_2＋2CO） was determined before and after hydrogen reduction, and under a flow of hydrogen. After hydrogen reduction, the limonite ore exhibited higher catalytic performance, because of the formation of Fe-Ni. However, the Fe in Fe-Ni was readily oxidized by the input CO_2 gas. resulting in a rapid decrease in the catalytic performance of limonite ore. The performance de- crease was due to a decrease in the Ni surface area; Ni could not dissolve in iron oxides and this caused segregation in the iron oxides. When the reaction was conducted under a hydrogen flow, the Fe-Ni was formed and maintained. Ni was highly dispersed in the Fe-Ni phase, resulting in greater surface area of Ni and higher conversion rate of CH_4 and CO_2. The catalytic performance of the limonite ore was inferior to the Ni/Al_2O_3 catalyst because the effect of catalyst support was small, however, the limonite ore was more stable during catalytic use and much cheaper than the Ni/Al_2O_3.
