CO2 absorption and desorption property of porous SiO2 with Co-MEA complex

•The Co-MEA complex, [Co(MEA)3]3+, were formed by adding Co(CH3COO)2 to a MEA solution.•The CO2 desorption property at 60 °C of the Co-MEA/SiO2 composite was superior to non-added MEA/SiO2.•The CO2 absorption capacity of Co-MEA/SiO2 was maintained even after the 10th repetition of absorption and desorption.

Various MEA solutions were prepared by adding M(CH3COO)2 (M = Ni, Co, Cu, Zn) to mono-ethanolamine (hereafter M-MEA solution) to improve the CO2 desorption property of MEA. From the FTIR spectra and UV-vis-NIR, it was found that the Co-MEA complex, [Co(MEA)3]3+, was formed in the Co-MEA solution. The Co-MEA solution including [Co(MEA)3]3+ showed an excellent CO2 desorption property at 60 °C, compared to Ni-MEA, Zn-MEA, Cu-MEA, and non-added MEA. Then, the Co-MEA/SiO2 composite was fabricated by impregnating Co-MEA to a mesoporous silica. The CO2 desorption property at 60 °C of the Co-MEA/SiO2 composite was also improved, similar with the Co-MEA solution. The CO2 absorption capacity at RT of the Co- MEA/SiO2 composite was lowered compared to than that of the non-added MEA/SiO2 composite. However, the CO2 absorption capacity of the Co-MEA/SiO2 composite was almost maintained even at the 10th repetition of CO2 absorption and desorption. Thus, it was found the Co-MEA/SiO2 composite was stable for CO2 absorption and desorption and was an appropriate material for improving the CO2 desorption behavior of MEA.

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