Electrochemically substituted metal phthalocyanines, e-MPc (M = Co, Ni), as highly active and selective catalysts for CO<inf>2</inf>reduction

Abstract

© The Royal Society of Chemistry 2018. Metal-oxide nanoclusters (NCs) such as FeO x , CoO x , and NiO x are incorporated into iron phthalocyanine (FePc) supported on graphene, MO x /FePc, via a facile self-assembly method. MO x /FePc electrocatalysts show high activity, selectivity and stability for the electrochemical CO 2 reduction reaction (CO 2 RR) as compared with the corresponding metal phthalocyanines, i.e., FePc, CoPc and NiPc, under identical test conditions. Near edge X-ray absorption fine structure (NEXAFS) spectroscopy reveals that MO x /FePc undergoes a metal ion replacement of the iron center of Pc, forming electrochemically substituted metal Pc, e-MPc where M = Co and Ni, co-existing with the replaced FeO x nanoparticles (NPs) in the vicinity of the e-MPc. The results indicate that the e-MPc with in situ dispersed FeO x NPs, FeO x /e-CoPc and FeO x /e-NiPc exhibits excellent activity, high selectivity and stability for the CO 2 RR.