Institute of Applied Chemistry, Jiangxi Academy of Sciences, 7777# ChangDong Avenue, Nanchang, Jiangxi Province 330096, China.
Institute of Applied Chemistry, Jiangxi Academy of Sciences, 7777# ChangDong Avenue, Nanchang, Jiangxi Province 330096, China.
J Colloid Interface Sci. 2021 Feb 1;583:40-49. doi: 10.1016/j.jcis.2020.09.022. Epub 2020 Sep 16.
KOH is one of the most widely used activators for the synthesis of highly porous carbon. However, the strong causticity of KOH could cause serious equipment damage and safety issues at high temperature. In the current work, we presented the synthesis of porous carbons with large surface area using four different potassium salts (CHCOOK, KHCO, KCO, and KCO·HO) as mild but effective activators. Hydrochar prepared from the hydrothermal carbonization of glucosamine hydrochloride was used as carbon precursor. The carbons exhibited specific surface area up to 2403 m/g. In order to reveal the different influences of nitrogen doping and textural properties under low and high pressure conditions, CO adsorption was tested with pressure up to 20 bar. At 1 bar, ultramicropore was the most determinant factor. Nitrogen doping also showed important influences, especially on the CO/N selectivity. At 20 bar, the carbon activated by KHCO showed CO uptakes of 26.24 (0 °C) and 18.63 mmol/g (25 °C). The experiment results indicated that the uptake at 20 bar correlated with the total surface area and total porosity of the carbon, and no apparent effects from nitrogen doping were observed.
KOH 是合成高多孔碳最常用的活化剂之一。然而，KOH 的强腐蚀性在高温下会导致严重的设备损坏和安全问题。在目前的工作中，我们使用四种不同的钾盐（CHCOOK、KHCO、KCO 和 KCO·HO）作为温和但有效的活化剂，合成了具有大表面积的多孔碳。以盐酸氨基葡萄糖水热碳化得到的水炭为碳前体。所制备的碳具有高达 2403 m/g 的比表面积。为了揭示在低压和高压条件下氮掺杂和结构性质的不同影响，采用高达 20 巴的压力进行了 CO 吸附测试。在 1 巴时，微孔是最决定性的因素。氮掺杂也表现出重要的影响，特别是对 CO/N 选择性的影响。在 20 巴时，由 KHCO 活化的碳在 0°C 时的 CO 吸附量为 26.24mmol/g，在 25°C 时为 18.63mmol/g。实验结果表明，20 巴时的吸附量与碳的总表面积和总孔隙率有关，氮掺杂没有明显的影响。
