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1.
Adv Mater ; 35(30): e2302467, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37074628

RESUMO

Metal phthalocyanine (MPc) material with a well-defined MN4 moiety offers a platform for catalyzing the oxygen reduction reaction (ORR), while the practical performance is often limited by the insufficient O2 adsorption due to the planar MN4 configuration. Here, a design (called Gr-MG -O-MP Pc) is proposed, where the metal of MPc (MP ) is axially coordinated to a single metal atom in graphene (Gr-MG ) through a bridge-bonded oxygen atom (O), introducing effective out-of-plane polarization to promote O2 adsorption on MPc. Manipulating the out-of-plane polarization charge by varying types of MP and MG (MP  = Fe/Co/Ni, MG  = Ti/V/Cr/Mn/Fe/Co/Ni) in the axial coordination zone of -MG -O-MP - are examined by density functional theory simulations. Among them, the catalyst of Gr-V-O-FePc stands out with the highest calculated O2 adsorption energy, which is synthesized successfully and verified by systemic X-ray absorption spectroscopy measurements. Importantly, it delivers a remarkable ORR performance with half-wave potential of 0.925 V (versus reversible hydrogen electrode) and kinetic current density of 26.7 mA cm-2 . This thus demonstrates a new and simple way to pursue high catalytic performance by inducing out-of-plane polarization in catalysts.

2.
Nanoscale ; 14(23): 8255-8259, 2022 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-35642926

RESUMO

Molecular Fe phthalocyanine (FePc) is successfully anchored on a defective mesoporous carbon framework for the highly efficient oxygen reduction reaction (ORR) with a half-wave potential of 0.86 V (vs. RHE) and a limited current density of 5.40 mA cm-2. DFT calculations further suggest that the non-planar structure incorporating FePc can promote charge polarization and decrease the energy barrier.

3.
Chem Commun (Camb) ; 58(17): 2914-2917, 2022 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-35138308

RESUMO

High curvature carbon-supported isolated NiN4 sites with ideal CO2 reduction reaction performance were obtained through a top-down strategy. The charge polarization induced by the axial asymmetry of the carbon substrate can enhance the adsorption of COOH* and reduce the free energy barrier of the rate-determining step.

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