Pore Modification and Phosphorus Doping Effect on Phosphoric Acid-Activated Fe-N-C for Alkaline Oxygen Reduction Reaction

Abstract

The price and scarcity of platinum has driven up the demand for non-precious metal catalysts such as Fe-N-C. In this study, the effects of phosphoric acid (PA) activation and phosphorus doping were investigated using Fe-N-C catalysts prepared using SBA-15 as a sacrificial template. The physical and structural changes caused by the addition of PA were analyzed by nitrogen adsorption/desorption and X-ray diffraction. Analysis of the electronic states of Fe, N, and P were conducted by X-ray photoelectron spectroscopy. The amount and size of micropores varied depending on the PA content, with changes in pore structure observed using 0.066 g of PA. The electronic states of Fe and N did not change significantly after treatment with PA, and P was mainly found in states bonded to oxygen or carbon. When 0.135 g of PA was introduced per 1 g of silica, a catalytic activity which was increased slightly by 10 mV at −3 mA/cm2 was observed. A change in Fe-N-C stability was also observed through the introduction of PA.

Influence of Ice Templating on Oxygen Reduction Catalytic Activity of Metal‐Free Heteroatom‐Doped Mesoporous Carbon Derived from Polypyrrole for Zinc–Air Batteries

“…In the O 1s spectra (Figure 3d) of F-ADC-1000, the deconvoluted peaks at 532.7 and 531.2 eV binding energies correlate to the O─C and O─H bonds, which are also present in the O-XDC-1000 sample (Figure S3d, Supporting Information). [16b] The P 2p spectra of F-ADC-1000 and O-XDC-1000 can be deconvoluted into three peaks (as shown in Figure 3e and S3e, Supporting Information) corresponding to the P-C coordination and the two oxidized forms of P. [41] The S 2p spectra of the F-ADC-1000 sample show two deconvoluted peaks observed at the binding energy values of 164.0 and 165.3 eV, corresponding to the S 2p 3/2 and S 2p 1/2 spin-orbit levels of sulfur (Figure 3f ). The minor peaks in the spectra at 168.0 and 169.08 eV correspond to the sulfate species.…”

A Gram Scale Soft-Template Synthesis of Heteroatom Doped Nanoporous Hollow Carbon Spheres for Oxygen Reduction Reaction

“…Due to their high thermal stability, good electric conductivity, and chemical inertness, nanoporous carbons are well-suited for a variety of applications in energy storage, conversion, and catalysis [ 3 , 4 , 5 ]. These physical and textural properties can be controlled by modifying their porous structures [ 6 , 7 ]. Heteroatoms such as nitrogen, as well as other atoms such as B, P, S, and O, are often incorporated into carbon structures to enhance their intrinsic physicochemical properties for energy and electrocatalytic applications, and this emphasizes the effect of carbon support [ 8 , 9 , 10 , 11 , 12 , 13 ].…”