The Effect of Synthesis Parameters for the Mesoporous Carbons Using Silica Aerogel Templates

2019-04-22
Hydrogen is considered as one of the most promising future energy carrier due to its high energy density and its production through ethanol steam reforming reaction (SRE) has the potential to be used for its on board production, in fuel cell powered motor vehicles. Nowadays, novel catalysts are investigated for the steam reforming of ethanol reactions in order to achieve high hydrogen yield with low coke formation. One of the novel catalyst is a mesoporous material templated mesoporous carbon. Mesoporous carbon materials are investigated due to their physical and chemical properties, such as electrical and thermal conductivity, mechanical and chemical stability, low density, high surface area, and large pore size. Using the mesoporous materials such as SBA-15, MCM-48 etc. as a template, having a high surface area and pore diameter carbon supports can be synthesized. Generally, hard template method is used to achieve well-defined ordered structure. Sucrose and furfuryl alcohol are used as carbon precursors and for the removal of silica materials, washing with HF or NaOH are applied. In this study, for the first time, silica aerogel was used as silica template. Moreover, sucrose was impregnated to the pores of the mesoporous materials as a carbon precursor. The effect of washing with HF or NaOH, adding silylating agent to silica aerogel in the synthesis and calcination temperature of silica aerogel on the structure of the materials were investigated. The results showed that high surface area materials with Type IV isotherm were synthesized. The carbon materials washed with HF gave higher surface areas compared to the materials washed with NaOH. It was evident that NaOH did not remove the all silica materials. This result also proved with the SEM and EDS analysis, showing the unremoved silica structures in the materials. In addition, washing with HF resulted in highly acidic carbon materials considering TPD analysis. When the silica aerogels which did not contain silylating agent as a template, the final carbon materials gave high surface area and pore diameter. Moreover, the calcination temperature of the silica aerogels did not affect the surface area and pore diameter of the carbon materials. The nickel was impregnated into these materials and they were tested in the steam reforming of ethanol reaction. The carbon material washed with HF suppressed the ethanol steam reforming reaction and favored the ethanol decomposition reaction, giving undesired products CH4 and CO. The hydrogen yield was 3.8 using the carbon material washed with NaOH as a catalyst.
2019 MRS Spring Meeting and Exhibit (22 - 26 Nisan 2019)

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Citation Formats
M. Sarıyer and N. A. Sezgi, “The Effect of Synthesis Parameters for the Mesoporous Carbons Using Silica Aerogel Templates,” presented at the 2019 MRS Spring Meeting and Exhibit (22 - 26 Nisan 2019), Phoenix, USA, 2019, Accessed: 00, 2021. [Online]. Available: https://hdl.handle.net/11511/78612.