Engineering Porphyrin Metal–Organic Framework Composites as Multifunctional Platforms for CO₂ Adsorption and Activation

Abstract

As an effective solution toward the establishment of a sustainable society, the reductive transformation of CO2 into value-added products is certainly important and imperative. Herein, we report a porphyrin metal–organic framework composite Au@Ir-PCN-222, which is obtained through the in situ formation of Au nanoparticles in the coordination interspaces of Ir-PCN-222. Catalytic results show that Au@Ir-PCN-222 is highly efficient for CO2 reduction and aminolysis, giving rise to formamides in high yields and selectivities under room temperature and atmospheric pressure. Mechanistic studies disclose that the high efficiency of Au@Ir-PCN-222 is due to the synergistic catalysis of Au NPs and Ir-PCN-222, in which Au NPs can adsorb CO2 molecules on their surfaces and then increase the CO2 concentration in the cavities of the framework, and at the same time, Au NPs transfer electrons to Ir-porphyrin units and therefore increase the interactions with CO2 molecules.