Enhancing the thermal stability of nanostructured carbonaceous materials using an improved method of template synthesis

In this work, an improved method of template synthesis including an additional post-carbonization stage has been developed. A sample of nanostructured carbonaceous material synthesized by this method was studied using low-temperature N 2 ad(de)sorption and derivatography and compared with the conventionally synthesized sample and the activated anthracite sample. Also, the acidity of the materials by Boehm titration and the effect of Ni introduction on thermal characteristics of the samples were evaluated. In the post-carbonized sample, the development of the external surface and mesoporosity in the nanoscale range of 6–20 nm was observed as well as a reduction in the number of micropores. This had a positive effect on the thermal stability of the material, which was confirmed by the calculated values of the combustion activation energy. The post-carbonization stage promoted the formation of a phase whose thermal stability was close to that in activated anthracite. In terms of thermal stability, this phase was also less sensitive to the negative effect of the introduction of Ni compared to the phases of the conventionally synthesized sample. The existence of phases with different thermal stability in nanostructured carbonaceous materials was interpreted in terms of differences in the local concentration of activity centers in the material. An increased thermal stability of the additionally carbonized material was explained by a reduction of its microporosity and, ultimately, a decrease in the number of activity centers (surface defects, acid sites, etc.), which are the factors that initiate the carbon combustion.