Reforming of Methane with Carbon Dioxide to Syngas over Ni-Co Bimetallic Catalysts

Reforming of CH 4 with CO 2 to give syngas over Ni/SiO 2, Co/SiO 2 and Ni Co/SiO 2 catalysts has been studied by activity evaluation using TPO, TPR and CO 2 TPD techniques. It is found that the catalysts without pre reduction decreased in their activities following the order of Ni Co/SiO 2~Ni/SiO 2Co/SiO 2, and Ni Co/SiO 2 was much less sensitive to coking and more stable than Ni/SiO 2 catalyst. The CH 4 conversion over Ni Co/SiO 2 catalyst increased with time in stream during the first 1 h period of reaction and then remained invariable with time in stream for 9 h, while over Ni/SiO 2 catalyst the CH 4 conversion decreased continuously with reaction time and the reaction had to be stopped because of the reactor becoming completely plugged by carbon deposits after 6 h. In the case of Ni Co/SiO 2 catalyst, Ni promoted the reduction of Co species, which was found beneficial to CO 2 adsorption and suppression of less active carbon deposition. This is considered to be related to the excellent activity, stability and anti coking property of the bimetallic catalyst.