The fluid catalytic cracking process is responsible for about 30% of CO2 emission in a petroleum refinery. The possibility to react CO2 and coke (Reverse-Boudouard reaction - RB) during the spent catalyst regeneration in the presence of CO2 and O-2 atmosphere, instead of air, can simultaneously mitigate CO2 emission and produce CO for sequential uses. This goal was achieved by using an alumina modified by vanadium and potassium. Catalysts composed of alumina modified by Li, Na, K, Mg and Ca were investigated. The modified alumina catalysts were active for RB reaction in the following order, K > Mg, Li > Ca, Na> pristine alumina. Alumina modified by vanadium and potassium was also studied and revealed itself a remarkably active catalyst under O-2 atmosphere, as well as for RB reaction. For instance, at 720 degrees C 50% of CO2 was converted to CO, this value increases to 90% at 800 degrees C. Finally, insights into RB reaction were provided performing this reaction in the presence of (CO2)-C-13. (C) 2014 Elsevier B.V. All rights reserved.