Effect of rate of pyrolysis on the textural properties of naturally-templated porous carbons from alginic acid

- Textural properties studied by N2 porosimetry and thermal gravimetric analysis.
- Mesoporosity of Starbon® decreases with increasing rate of pyrolysis.
- Porosity collapse a result of rapid volatile compound generation during fast pyrolysis.
- Increased pyrolysis rate decreases adsorption capacity of Starbon®.

The effect of pyrolysis rate on the properties of alginic acid-derived carbonaceous materials, termed Starbon®, was investigated. Thermal Gravimetry-IR was used to prepare porous carbons up to 800 °C at several rates and highlighted increased CO2 production at higher pyrolysis rates. N2 porosimetry of the resultant carbons shows how pyrolysis rate affects both the mesopore structure and thus surface area and surface energy. Surface capacity of these carbons was analysed by methylene blue dye adsorption. In general, as the rate of pyrolysis increased, the mesopore content and adsorbent capacity decreased. It is considered here that the rapid production of volatiles at these higher rates causes structural collapse of the non-templated pore network. The work here demonstrates that pyrolysis rate is a key variable which needs to be controlled to maximise the textural properties of Starbon® required for adsorption applications.

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