基于密度泛函理论的活性炭孔径分布改进算法

发布时间：2018-02-14 07:34

本文关键词： 氩活性炭吸附分布密度泛函理论　出处：《化工学报》2017年09期 　论文类型：期刊论文

【摘要】：为提高非定域密度泛函理论(NLDFT)预测活性炭孔径分布(PSD)的精度,考虑了活性炭孔壁面晶体粗糙度对结果的影响。在传统NLDFT基础上,结合吸附壁面碳原子的密度分布,推导出改进NLDFT,预测了氩在光滑及具粗糙碳晶体表面的吸附平衡,并根据87.3 K、氩在活性炭上的吸附平衡数据,在由两种NLDFT确定了不同孔径的理论等温线核后,由寻优函数确定活性炭在0.35~12 nm区间的PSD。结果表明,以改进的NLDFT预测活性炭的PSD时,确定的活性炭孔径呈连续分布,预测平衡数据的相对误差小于10%;传统NLDFT确定的孔径在1 nm处出现断点,最大的预测相对误差范围达45%。改进NLDFT能较准确预测氩在具有粗糙晶体碳表面活性炭的PSD。
[Abstract]:In order to improve the accuracy of nonlocal density functional theory (NLDFTs) in predicting the pore size distribution of activated carbon (PSD), the effect of crystal roughness on the pore surface of activated carbon was considered. Based on the traditional NLDFT, the density distribution of carbon atoms on the adsorbed wall was combined. The modified NLDFTs were derived, and the adsorption equilibrium of argon on smooth and rough carbon crystal surfaces was predicted. According to the adsorption equilibrium data of 87.3 K and argon on activated carbon, the theoretical isotherm nuclei with different pore sizes were determined by two kinds of NLDFT. The PSDs of activated carbon in the range of 0.35 ~ 12 nm were determined by optimization function. The results showed that the pore size of activated carbon was continuously distributed when the modified NLDFT was used to predict the PSD of activated carbon. The relative error of the predicted equilibrium data is less than 10, the pore diameter determined by traditional NLDFT is broken at 1 nm, and the maximum relative error range is 45. The improved NLDFT can accurately predict argon in PSDs with activated carbon on rough crystal surface.
【作者单位】：福建省船舶与海洋工程重点实验室集美大学轮机工程学院;
【基金】：国家自然科学基金项目(51679107) 福建省自然科学基金项目(2015J01216)~~
【分类号】：O641.1;TQ424.1

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