(662f) High Capacity Ammonia Adsorption On Functionalized Carbon Materials

Porous carbon materials are functionalized using acid treatment. Ammonia adsorption capacity and adsorption dynamics are characterized using high pressure ammonia adsorption at room temperature. The oxygen content and type of functional groups were characterized using XPS, FITR spectroscopy and EELs pattern. Our study showed microporous carbons with little mesoporosity and hierarchical structure were ideal for acid treatment and then ammonia adsorption. The highest uptake was achieved at on a microporous carbon with more than 1 cc/g pore volume and acid treatment for 1 hr at 90 ºC. The ammonia uptake was 17 mmol/g at 1 bar and 25 ºC with 14 mmol/g reversible adsorption capacity. The synergy between high adsorption affinity of the oxidized surface and strong attractive forces between the adsorbed ammonia molecules increased ammonia adsorption on the carbons. Here we observed having a portion of ammonia irreversibly adsorbed to the adsorbent surface is actually helpful to rise the reversible capacity as well.