Ni supported on La2O3+ZrO2 for dry reforming of methane: The impact of surface adsorbed oxygen species

This research investigates the effect of doping Ni/La₂O₃+ZrO₂ with nitrates of Ca, Cr, Ga, and Gd on the conversion of the feed and H₂/CO molar ratio. The development of these catalysts is intended to tackle inefficiency of dry reforming of CH₄ which stems from deactivation and sintering of active metal. All promoted catalysts perform better than the un-promoted catalyst. Cr promoted sample gives the best performance with CH₄ and CO₂ conversion averaging 83 and 88% respectively. Also, it maintains good stability. The relative ease of reducing the catalyst plus its porous nature are responsible for its performance. Ca promoted sample has the same area as that of the support indicating the movement of Ni–Ca out of the pores of the support during calcination. According to thermogravimetric analysis, the un-promoted catalyst records the highest amount of carbon while the Ca promoted sample has about 18%.