Based on results of aforementioned characterisation, we can infer that during the OER process of the highly dispersed pseudoamorphous metal phosphide cluster supported by N-C layer (Fig. S21), OH species will first adsorbon the metal sites (M OH*) on the materialsurface, and then convert into O* (M O *), resulting in the O* peak at 1050 cm 1 in the Raman spectrum, and then forming the new OER active species MOOH and then O2 can be further generated [55,57]. During OER, the metal phosphate on the surface of (NiFeCo)2P-PA/NF was dissolved in the electrolyte, so the XPS peak of the P-O almostdisappeared (Fig. 5h), and the content of P and O in the elementmappings and EDS decreased (Fig. S22). At the same time, the content of C and N at the edge of the catalyst layer is higher than that of other elements [61]. Because of the stable existence of (NiFeCo) 2P-PA/NF and the dissolution of metal phosphate on the catalyst surface during the OER process, more (NiFeCo)2P-PA in the catalystlayer is exposed, so that the XPS peak of the CoP bond is significantly enhanced (Fig. S20b).