Suppression of carbon formation in CH_4–CO_2 reforming by addition of Sr into bimetallic Ni–Co/γ-Al_2O_3 catalyst

Bimetallic catalysts, containing 5 wt% Ni +5 wt% Co supported on γ-Al_2O-3 combined with different amounts of Sr promoter ranging from 0 to 1 wt%, for dry reforming reaction were prepared by the impregnation method. The dry reforming reaction was carried out at atmospheric pressure using CO_2/CH-4/N-2 feed ratio of 17/17/2, F/W= 60 mL/min g_cat and reaction temperature range of 500–700 °C. The performance of the developed catalyst was evaluated by estimating theCH4 and CO_2 conversions, and by performing a long run stability test. The fresh and spent catalysts were characterized by BET, TGA, TPD, TPR, and TPO. The bimetallic catalysts provided higher activity than the monometallic-catalysts. When the bimetallic was promoted with Sr, the activity decreased slightly however, the stability enhanced. The best stability, estimated by the deactivation factor, and less carbon deposition, measured by TGA, were obtained when 5Ni5CoSr0.75 catalyst was used.