(601h) Physical Activation of Microcrystalline Cellulose for High-Surface Area Carbon Materials

Microcrystalline cellulose (MCC) is a promising precursor for additive manufacturing of active carbon due to its colloidal stability and ease of printing via extrusion-based methods. Carbonization of MCC prints can yield high-surface area carbon materials in complex shapes, offering a novel route to low cost, rapid manufacturing of detailed adsorbent structures with applications as filters, CO₂ capture, and reactive C templates. However, MCC carbonization is generally low yield (~10 wt%) and lengthy (~days-weeks).

In this study, we explore controlled carbonization in inert atmosphere to result in high-purity, high-surface area char from MCC in yields exceeding 20% and in less than 3 days. First, we use thermogravimetric analysis and in-line mass spectrometry (TGA-MS) to determine at what temperatures (< 300^oC) is char formation favorable over tar formation. Next, we use TGA-MS and combustion analysis (for %C) to determine the effect of carbonization temperature on the time requirement for the low-temperature reaction. Then, we evaluate the efficacy of our low-temperature dwell after full carbonization (to 900^oC) by characterization of the carbon content and specific surface area of the resultant char. Finally, we investigate the applicability of the carbonization schedule to a wide range of initial MCC sample size.