Structures, physicochemical properties and oxygen reduction activities of carbons derived from ferrocene-poly(furfuryl alcohol) mixtures

Abstract

The structure, physicochemical properties and oxygen reduction abilities of carbons prepared by the carbonization of mixtures of ferrocene and poly(furfuryl alcohol) were studied. X-ray diffraction (XRD), Raman spectroscopy and transmission electron microscopy (TEM) studies revealed that the carbons thus prepared consisted of two components; amorphous and turbostratic shell-like components. The fraction, f sharp , obtained by the analysis of the (002) peak in XRD was found to be a parameter that represented the degree of formation of the shell-like components. The formation of the shell-like components induced an increase in the mesopore volumes. Electrical conductivity increased exponentially with f sharp , which indicated that the conduction process was governed by a percolation process of the conductive shell-like components. The amount of CO-desorption by O 2 -TPD technique showed a maximum desorption at f sharp =0.3, and the further development in the sharp component led to a decrease in the CO-desorption. Mo¨ssbauer spectroscopy technique revealed the presence of a-Fe, c-Fe, Fe 1-x O and Fe 3 C in the prepared carbons, which were soluble species to acids. The oxygen reduction activity was studied in a oxygen saturated sulfuric acid solution by rotating disk electrode voltammetry. The oxygen reduction potential varied with f sharp ; initially it increased by f sharp =0.3 and then it decreased at higher f sharp values. This behavior was similar to that of CO-desorption, which meant the presence of an adequate degree of the development of the shell-like structure for maximizing oxygen adsorption. Removal of the surface metal component from the carbons by acidwashing resulted in no decrease in the oxygen reduction activities of the carbons. The nature of the active sites on the carbon materials is discussed.

Nanoshell-Containing Carbon Cathode Catalyst for Proton Exchange Membrane Fuel Cell from Herbaceous Plants Lignin

“…LG (10) LG (14) (a) (b) development of NS structures shown in Figure 2 as we have claimed in the previous studies [1,6]. (3), which had almost the same f sharp as LG(3) (Figure 2).…”

“…We definitely demonstrated the conversion of LG into NSCC by the carbonization in the presence of NS forming catalyst, CoPc in the present case, likewise for conventional synthetic polymers such as furan resin [1,2], oxine-formaldehyde resin [3], furfuryl alcohol [4][5][6], and phenol-formaldehyde resin [7,8] that we have employed previously.…”

“…Nanoshell (NS) is a type of nanocarbon, whose structure is hollow spherical shape with a diameter of 20 -50 nm by stacking of hexagonal carbon layers. We have prepared NSCCs using synthetic polymer based materials such as furan resin [1,2], oxine-formaldehyde resin [3], furfuryl alcohol [4][5][6] and phenol-formaldehyde resin [7,8]. In the reports we have mentioned that NS structure and nitrogen played important roles to improve ORR activities of carbon materials.…”

Formation of graphite zigzag edges by cathodic electrochemical etching in acidic solution

“…Graphene edges are now gaining much attention regarding the electrocatalysis in a cathodic environment (carbon-alloy catalysis [15][16][17][18][19][20][21]). …”

Preparation of Carbon Alloy Catalysts from a Polyhydroxyamide with Iron Phthalocyanine via a Poly-biphenylenebisoxazole Composite

“…In C-DHBTA (which contains no Fe) a broad diffraction peak D A originating from amorphous carbon was observed. In C-DHBTA-1, D T which corresponds to a turbostratic carbon structure [23,24] is observed with a wider angle and larger full width at half maximum (FWHM), due to the duplication of D T and D A shown in Table 2. Table 2.…”