Abstract
Carbon materials for electrical energy devices, such as battery electrodes or fuel-cell catalysts, require the combination of the contradicting properties of graphitic microstructure and porosity. The usage of graphitization catalysts during the synthesis of carbide-derived carbon materials results in materials that combine the required properties, but controlling the microstructure during synthesis remains a challenge. In this work, the controllability of the synthesis route is enhanced by immobilizing the transition-metal graphitization catalyst on a porous carbon shell covering the carbide precursor prior to conversion of the carbide core to carbon. The catalyst loading was varied and the influence on the final material properties was characterized by using physisorption analysis with nitrogen as well as carbon dioxide, X-ray diffraction, temperature-programmed oxidation (TPO), Raman spectroscopy, SEM and TEM. The results showed that this improved route allows one to greatly vary the crystallinity and pore structure of the resulting carbide-derived carbon materials. In this sense, the content of graphitic carbon could be varied from 10–90 wt % as estimated from TPO measurements and resulting in a specific surface area ranging from 1500 to 300 m2·g−1.
Highlights
Carbon is a versatile material that has been widely utilized in many applications such as adsorption [1,2,3], catalysis [4,5], catalyst support [6,7,8], molecular sieves [9,10] and energy storage [11,12,13], owing to its large specific surface area and distinct pore character
The results showed that this improved route allows one to greatly vary the crystallinity and pore structure of the resulting carbide-derived carbon materials
The adsorption–desorption curve shows a similar shape compared to a typical fully carbide-derived carbon (CDC) material synthesized at 800 °C but features a lower uptake due to the mass of the non-porous carbide core [15]
Summary
Carbon is a versatile material that has been widely utilized in many applications such as adsorption [1,2,3], catalysis [4,5], catalyst support [6,7,8], molecular sieves [9,10] and energy storage [11,12,13], owing to its large specific surface area and distinct pore character. For applications in which electrical conductivity plays an important role, e.g., battery electrodes, fuel-cell catalysts or supercapacitors [14,15,16], it is necessary for carbon to show porosity and to feature a graphitic structure. The reason is that graphitic carbon consists of crystalline sp2hybridized fractions that induce high electron conductivity. Many synthetic approaches were employed to produce carbon combining porosity and graphitic structure [17,18,19]. Depending on the carbide and parameters employed during the synthesis, CDC can be varied from extremely amorphous to highly crystalline microstructures and from ultramicro- to mesoporous pore structures. CDC is known as material with tunable microstructure and pore structures [20]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
