The possibility of performing the regeneration of spent fluid catalytic cracking catalysts in rich CO2 atmosphere can simultaneously reduce greenhouse gas emissions and produce CO for sequential uses. Herein alumina modified by vanadium and lithium was revealed a remarkable catalyst (or additive) for this goal. High CO2 conversion was observed in the presence of helium (for instance at 720 and 800 degrees C, 39 and 76% of CO2 was converted during the first 5 min of reaction respectively) and it was reduced by less than 5% in the presence of oxygen. Moreover the catalyst works effectively regardless the coke type on spent catalyst, i.e. produced by means of hydrocarbon or bio feed cracking. This catalyst was tested as an additive and works properly up to one part to ten of spent USY. By means of either labeled CO2 or coke (both with carbon 13) it was shown that primary (CO2)-C-13 forms (CO)-C-13 followed by oxygen mobility between alumina and USY promoting coke oxidation. (CO2)-C-12 formed in-situ similarly to (CO2)-C-13 readily reacts with coke producing CO. These effects improve the coke burning by CO2 and remarkably increase the CO/CO2 ratio even in the presence of O-2. Finally these results strongly support that the FCC regeneration step can be kept under auto-thermal condition in CO2 rich atmosphere. (C) 2016 Elsevier B.V. All rights reserved.