• Mladenović, Dušan
• Šljukić, Biljana
• Radinović, Kristina
• Pombeiro, Armando
• Hazra, Susanta
• Paul, Anup
• Silva, M. Fátima C. Guedes Da

Abstract

<jats:p>The new 3D coordination polymer (CP) [Mn(L)(HCOO)]n (Mn-CP) [L = 4-(pyridin-4-ylcarbamoyl)benzoate] was synthesised via a hydrothermal reaction using the pyridyl amide functionalized benzoic acid HL. It was characterized by elemental, FT-IR spectroscopy, single-crystal and powder X-ray diffraction (PXRD) analyses. Its structural features were disclosed by single-crystal X-ray diffraction analysis, which revealed a 3D structure with the monoclinic space group P21/c. Its performance as an electrocatalyst for oxygen reduction (ORR), oxygen evolution (OER), and hydrogen evolution (HER) reactions was tested in both acidic (0.5 M H2SO4) and alkaline (0.1 M KOH) media. A distinct reduction peak was observed at 0.53 V vs. RHE in 0.1 M KOH, which corresponds to the oxygen reduction, thus clearly demonstrating the material’s activity for the ORR. Tafel analysis revealed a Tafel slope of 101 mV dec−1 with mixed kinetics of 2e− and 4e− pathways indicated by the Koutecky–Levich analysis. Conversely, the ORR peak was not present in 0.5 M H2SO4 indicating no activity of Mn-CP for this reaction in acidic media. In addition, Mn-CP demonstrated a noteworthy activity toward OER and HER in acidic media, in contrast to what was observed in 0.1 M KOH.</jats:p>

Topics

• polymer
• Oxygen
• powder X-ray diffraction
• Hydrogen
• Fourier transform infrared spectroscopy
• space group