CO2 Capture and Conversion Using a Cobalt(III) Schiff Base Complex as a Catalyst at Ambient Conditions

CO₂ emissions must be reduced by at least 50 % by 2050, and hence the technical solutions to capture and convert CO₂ into value-added products should be considered. A Cobalt(III) Schiff base complex (Salen-Co(III)) has been investigated as a catalyst for synthesis of cyclic carbonate from CO₂ and epichlorohydrin(ECH) with tetrabutylammonium bromide (TBAB) as co-catalyst. To recover Salen-Co(III) for the next cycling operation, it was immobilized onto zeolite 13X through excessive impregnation method. The immobilized catalyst was characterized using XRD, SEM, BET and ICP-AES techniques. Catalytic tests showed that yield of cyclic carbonate reached 90 % using 0.5 mol % Salen-Co(III) at ambient conditions. The immobilized Salen-Co(III) exhibited better catalytic activity than the homogenous one when used at the first cycle, but the yield decreased by some 20 % after five cycles.