林产化学与工业2025，Vol.45Issue(5)：43-54,12.DOI:10.20195/j.issn.0253-2417.2023119
氨气/二氧化碳混合气体活化制备含氮活性炭的研究
Investigation on Preparation of Nitrogen-containing Activated Carbons by the Novel NH3/CO2 Activation Technology
摘要
Abstract
Using bamboo as the starting material,a systematic investigation had been carried out to provide insight for the evolution of pore structure,surface chemical properties and the activation mechanism during the NH3/CO2activation.The pore structure and adsorption capacity of the activated carbons were studied by analyzing the nitrogen adsorption isotherms and testing the adsorption capacity evolution.The methods of the elemental analysis,X-ray photoelectronic energy spectra,and Boehm titration were used to evaluate the chemical structure of activated carbons.X-ray diffraction and Raman spectroscopy were employed to reveal the evolution of microstructure of carbons in the process of activation.Gas chromatography was used to off-line analyze the composition of the gaseous production in the NH3/CO2 activation.The results showed that the NH3/CO2 activation could efficiently activate charcoals and obtain high-surface area nitrogen-containing activated carbons with the surface area of＞2 000 m2/g,nitrogen content of＞6％and high adsorption capacity at 950 ℃.Generally,three stages occured in the NH3/CO2 activation.The first stage was characteristic of the gasification of deposited oils in the bamboo charcoals by reacting with the mixture of ammonia and carbon dioxide,formation of supermicropores,low ablativity and the highest activation efficiency.In the subsequent second stage,the graphitic crystallites in bamboo charcoals were initially gasified leading to the combined formation of micropore and mesopores,and the activation efficiency was gradually decreased.In the third stage,the ablativity exceeded 50％,the NH3/CO2 mixture further react with the basal layer of the graphitic crystallites predominantly producing mesopores and a low activation efficiency.Structurally,the activation experiences the two stages of amorphous and subsequently crystalline regions.In the temperature range of 850-950 ℃,the NH3/CO2 activation leads to the formation of the nitrogen-containing functional groups with a majority of pyridine-N,pyrroline-N and quaternary-N and a minor of pyridine-N-oxides,where the presence of carbon dioxide promots the evolution of nitrogen-containing groups.The analysis of gaseous products revealed that ammonia and carbon dioxide jointly and synergistically activated charcoals promoting the formation of pore structure.The achievement obtained from this investigation could theoretically and technically provide substantial support for large-scale manufacture and application of nitrogen-containing activated carbons.关键词
NH3/CO2活化/含氮活性炭/孔隙结构/表面化学结构/活化机理Key words
NH3/CO2 activation/nitrogen-containing activated carbons/pore structure/surface chemical property/activation mechanism分类
化学工程引用本文复制引用
马浩桐,左宋林,张莉,崔难难..氨气/二氧化碳混合气体活化制备含氮活性炭的研究[J].林产化学与工业,2025,45(5):43-54,12.基金项目
国家重点研发计划资助项目(2019YFB1503804) （2019YFB1503804）
