Catalytic Activity of MWCNTs Doped with Some Transition Metal Phthalocyanines and Modified with Silver in ORR

Abstract

Bimetallic oxygen reduction reaction (ORR) catalysts based on multi-walled carbon nanotubes (MWCNTs) doped with cobalt, copper, and nickel phthalocyanines and modified with silver (MWCNT–CoPc–Ag, MWCNT–CuPc–Ag, and WMCNT–NiPc–Ag) were obtained using high-temperature synthesis. The synthesis was carried out at 900°C in a nitrogen atmosphere. Scanning electron microscopy (SEM), low-temperature nitrogen adsorption–desorption, Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and powder X-ray diffraction (XRD) were used to determine the physicochemical properties of the synthesized catalysts. The effect of high-temperature synthesis on the textural and morphological properties of materials was also studied. It was shown that the physicochemical parameters of materials largely depend on the nature of the metal in the composition of original phthalocyanine. The electrocatalytic activity of the materials was studied by linear voltammetry in a three-electrode cell with a rotating disk electrode and mercury oxide reference electrode. The MWCNT–CoPc–Ag catalyst showed high electrocatalytic activity in ORR, comparable to that of a commercial platinum catalyst, as well as high corrosion resistance.