以天然沸石为研究对象,研究焙烧温度对沸石总孔体积、孔径分布、表面Zeta电位、阳离子交换容量、晶体结构、硅铝配位结构和原子结合能等物化特性和颗粒结构的影响规律。结果表明:当焙烧温度≥600℃时,沸石总孔体积明显升高,其中微孔、介孔体积比例大幅减少,大孔体积比例大幅增加;随着焙烧温度升高,沸石颗粒表面Zeta电位逐渐升高,而沸石阳离子交换容量则先升高后降低,在400℃时达到最大值1.786 mmol/g。焙烧对沸石作用机理研究发现,沸石焙烧后,颗粒结晶度降低、晶胞小幅收缩;焙烧会使沸石中的Si(2Al)和Si(3Al)减少、Si(0Al)增加,且使沸石Al2p结合能小幅升高、Si2p结合能小幅下降、O1s的结合能则几乎不发生变化。
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 (2A1) coordination structure and Si (3A1) coordination structure decrease and the amounts of Si (0A1) coordination structure increase. The results of X-ray photoelectron spectroscopy analysis show that the electron binding energies of A12p increase slightly, the electron binding energies of Si2p decrease slightly, and the electron binding energies of O1s has little change.