An investigation of CO2 conversion capacity for PCN series doped with different 3d ions (Fe2+, Co2+ and Cu2+)

Abstract

Three porphyrinic Zr-MOFs (PCN-222, PCN-224 and PCN-226) doped with transition metals (Fe2+, Co2+ and Cu2+) are investigated for the potential application in carbon neutral, including the CO2 capture and conversion capacity as well as the stable cyclicity in the changeable environment. Based on the obtained structure properties, the adsorption quantities of CO2 and adsorption energies of the active sites (Fe2+, Co2+ and Cu2+) are calculated for the three PCN systems. As for the conversion capacity of these PCNs, the entire reduction pathway from CO2 to CH4 via an eight-electron transfer process is depicted by calculating the free energy (ΔG) and the energy barrier (ΔE), which can be modified by the different 3d ions doping. From the high separation efficiency of the products (CH4/CO2) and stability (thermostability in high temperature), the recyclability of these PCN is ultimately evaluated and found favorable for the industrial utilization. Therefore, the present work significantly supports that transition metals doping in different MOFs could yield the promising carbon capture and utilization (CCU) properties.