(1. 北京科技大學 能源與環(huán)境工程學院,北京 100083;
2. 北京科技大學 工業(yè)典型污染物資源化處理北京市重點實驗室,北京 100083)
摘 要: 以天然沸石為研究對象,研究焙燒溫度對沸石總孔體積、孔徑分布、表面Zeta電位、陽離子交換容量、晶體結(jié)構、硅鋁配位結(jié)構和原子結(jié)合能等物化特性和顆粒結(jié)構的影響規(guī)律。結(jié)果表明:當焙燒溫度≥600 ℃時,沸石總孔體積明顯升高,其中微孔、介孔體積比例大幅減少,大孔體積比例大幅增加;隨著焙燒溫度升高,沸石顆粒表面Zeta電位逐漸升高,而沸石陽離子交換容量則先升高后降低,在400 ℃時達到最大值1.786 mmol/g。焙燒對沸石作用機理研究發(fā)現(xiàn),沸石焙燒后,顆粒結(jié)晶度降低、晶胞小幅收縮;焙燒會使沸石中的Si(2Al)和Si(3Al)減少、Si(0Al)增加,且使沸石Al2p結(jié)合能小幅升高、Si2p結(jié)合能小幅下降、O1s的結(jié)合能則幾乎不發(fā)生變化。
關鍵字: 天然沸石;焙燒溫度;物化性能;Zeta電位;核磁共振
(1. School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China;
2. Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing 100083, China)
Abstract:The effects of calcination temperature on the physicochemical properties were studied with the natural zolite as the study object. The results show that the total pore volumes of the modified zeolite increase significantly when the calcination temperature is higher than 600 ℃. Among them, the percentages of microporous and mesoporous volumes reduce greatly, but the percentage of macrospore volume increases greatly. Zeta potentials of the zeolite increase with increasing the calcination temperature. The cation exchange capacity of the modified zeolite increases slightly at first, and subsequently decreases. The cation exchange capacity reaches the largest value of 1.786 mmol/g at 400℃. X-ray diffraction analyses show that the modified zeolite has a lower crystallinity and contractile unit cell. The results of nuclear magnetic resonance analysis indicate that the amounts of Si (2Al) coordination structure and Si (3Al) coordination structure decrease and the amounts of Si (0Al) coordination structure increase. The results of X-ray photoelectron spectroscopy analysis show that the electron binding energies of Al2p increase slightly, the electron binding energies of Si2p decrease slightly, and the electron binding energies of O1s has little change.
Key words: natural zeolite; calcinations temperature; physicochemical property; Zeta potential; nuclear magnetic resonance


