Modification of Co/TiO2 for dry reforming of methane at 2 MPa by Pt, Ru or Ni Original Research Article

Influences of an addition of trace amounts of Pt (Pt/Co=0.005–0.05 in atomic ratio) or Ru (Ru/Co=0.01–0.05) and of replacement of Co by Ni (Ni:Co=1:99–100:0) to 0.5 wt.% Co/TiO2 have been investigated for the dry reforming of methane at 2 MPa. Co/TiO2 reduced at 1123 K showed slow deactivation due to oxidation of Co. The addition of noble metals improved the catalytic stability of Co/TiO2 drastically. The strong resistant nature of Co/TiO2 to coke deposition was also retained by the catalysts. TPR revealed that noble metals improved the reducibility of cobalt oxide. The replacement of Co by a small amount of Ni also enhanced the catalytic stability of Co/TiO2, but replacement by an excess of Ni resulted in the decrease of catalytic stability because of coking. CoNi/TiO2 with an optimum Co:Ni ratio of 90:10 presented high stability with only an insignificant amount of coke deposition under 2 MPa, where coke deposition is highly favorable.