Formation of carbon nanofibers with Ni catalyst supported on a micro-mesoporous glass
| Autor: | I. Martín-Gullón, J. Sanguino, Juan Rubio, M.A. Mazo |
|---|---|
| Přispěvatelé: | Universidad de Alicante. Departamento de Ingeniería Química, Residuos, Energía, Medio Ambiente y Nanotecnología (REMAN) |
| Rok vydání: | 2021 |
| Předmět: |
Ni/SiO2 catalyst/support system
Materials science Catalytic chemical vapor deposition Vycor process 02 engineering and technology Porous glass 010402 general chemistry 01 natural sciences Catalysis Carbon source General Materials Science Porosity Carbon nanofiber General Chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics Microstructure 0104 chemical sciences CNFs/glass materials Ingeniería Química Chemical engineering Mechanics of Materials Carbon nano fibers 0210 nano-technology Mesoporous material |
| Zdroj: | RUA. Repositorio Institucional de la Universidad de Alicante Universidad de Alicante (UA) |
| Popis: | The Ni/SiO2 system is one of the most interesting to produce COx-free H2 and valuable carbon nanofibers (CNFs) by the catalytic decomposition of CH4. SiO2 is one of the most effective support while Ni catalyst displays long life and high activity. We studied the catalytic chemical vapor deposition (CCVD) process of CH4 within Ni/glass system at relatively low temperature (600 °C) during long times (3 h), varying the amount of the catalyst (2.3–17.8% Ni(%)) and the carbon source (100:200 to 100:0, CH4:N2). As the amount of Ni and CH4 increases, the formation of CNFs is enhanced giving as a result CNFs/glass materials with more amount, longer and thicker CNFs. The initial microstructure of the glass support and the way of Ni catalyst is deposited play a decisive role. Pristine porous glass displays a microstructe of interconnected mesopores which are progressively filled with Ni, producing ink-bottle pores with open ends. After the CCVD process as the amount of Ni or CH4 increases, the porosity of the Ni-doped glass is reduced due to the progressively filling of the mesopores (4 nm) with CNFs. Furthermore, due to the formation of large entanglements of CNFs new pores appear (20–70 nm) depending on the processing conditions. Fish-bone with hollow core and bamboo-like CNFs are found over the surface and also inside the porous glass support. It is observed a base-growth mechanism due to the strong interaction between the catalyst and the support, which prevents the Ni deactivation enhancing its activity for long times. This work was supported by project MAT2016-78700-R financed by Spanish Research Agency and European Regional Development Fund (AEI/FEDER, EU). |
| Databáze: | OpenAIRE |
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