Research On Electrocatalytic Reduction Of Oxygen And Electronic Structure Of Metallophthalocyanines

Substituted Metallophthalocyanies (Fe, Co, Ni) have been synthesized and identified by, IR, UV-Vis and X-ray photoelectron spectra (XPS) analysis. The glassy carbon electrodes modified with substituted metal-phthalocyanines were prepared.The catalytic properties of the modification glassy carbon electrodes about oxygen electro-reduction were investigated by the cyclic voltametry (CV) in three-electrode system. The affection on catalytic activity was studied in various substituted group and different pH value of support electrolyte solution. The result shows, FePc derivatives only have the catalytic activity in PH>7, their activity is arranged in group order: FeTCPc > FeTAPc > FeTNPc; CoPc derivatives have the excellent catalytic activity in both the acid electrolyte and the basic electrolyte solutions, their activity is arranged in group order: CoTNPc > CoTAPc > CoTCPc; NiPc derivatives shows no catalytic activity.DFT calculations on cobalt phthalocyanine and substituted phthalocyanine (CoTAPc, CoTCPc, CoTNPc, NiTCPc) have been carried out. The charge distribution, spin multiplicities, total energies, the frontier molecular orbital composition and energies have been analyzed. According to the result of calculations, this paper also present a theoretical study of the donor-acceptor intermolecular hardness (ηDA) associated with the interaction between CoPc, CoPc(X)4 and molecular oxygen. The result show that the electron-withdrawing groups increase the catalytic activity of substituted CoPcs for the reduction of oxygen and electron-donating groups have the opposite effect. The research indicate that the donor-acceptor intermolecular hardnessηDA possesses a predictive value in determining the catalytic activity of metallophthalocyanines.