Carbon deposition on borated alumina supported nano-sized Ni catalysts for dry reforming of CH4

► B2O3 influences the activity and stability of the Ni/Al2O3 catalysts significantly. ► No linear relationship between the Ni particle size and the catalyst activity/stability at 700 °C. ► 5 wt% B2O3 promoted Ni catalyst shows significantly improved stability. ► O-H groups regenerated during reaction play crucial role in carbon removal: C⁎+OH→COH⁎→CO+H⁎. ► A dissociative reaction mechanism over borated-alumina supported Ni catalysts is proposed.