在不添加外源性化学活化剂的条件下直接碳化乌拉草制备了多孔碳材料Ula C-950-HF.样品的碳含量高达93%,并且显示出部分石墨化的趋势.热重分析(TGA)结果显示样品具有很高的热稳定性(400℃前失重仅3%).N_2吸附-脱附测试结果表明样品的孔结构以微孔为主(峰值在1.1 nm),并有少量的介孔,总体的孔分布范围较窄,孔结构为有利于甲烷吸附的狭缝状.体积法测试结果表明,在298 K,3.5 MPa条件下,乌拉草基多孔碳材料Ula C-950-HF的甲烷储存能力达到208 mg/g(质量分数17%)或体积容量达到232 m L/m L.通过对产品的孔结构绘制模型并进行分析,从理论上初步解释了样品拥有较高的高压甲烷储存能力的原因.
Carex meyeriana Kunth was chosen as raw material to prepare porous carbon material( Ula C-950-HF) by the direct carbonization method without adding exogenous chemical activator. The result of analysis showed that the percentage of carbon in the sample was up to 93% and the product had a trend of part graphitizing. TGA result showed that the sample had high thermal stability( only 3% mass loss from 0 to 400 ℃). N_2 sorption isotherm results showed that the pore structure of porous carbon was mainly microporosity( maximal pore size distribution was 1.1 nm) with a small amount of mesoporous pore. The distribution of pore diameter was narrow. There were slit-like structures in the sample which were beneficial for storaging high-pressure methane. The capacity of methane storage of Ula C-950-HF was up to 208 mg/g( mass fraction,17%) or volumetric capacity of 232 at 298 K and 3.5 MPa. This paper also explained the reason for the outstanding capacity of storaging high-pressure methane by drawing a theoretical model.