Abstract:
We studied the mechanism underlying the solid-phase adsorption of a heavy rare-earth element (HREE, Yb) from acidic solutions employing MCM-22 zeolite, serving as both a layered synthetic clay mimic and a new platform for the mechanistic study of HREE adsorption on aluminosilicate materials. Mechanistic studies revealed that the adsorption of Yb(III) at the surface adsorption site occurs primarily through the electrostatic interaction between the site and Yb(III) species. The dependence of Yb adsorption on the pH of the solution indicated the role of surface charge, and the content of framework Al suggested that the Brønsted acid sites (BAS) are involved in the adsorption of Yb(III) ions, which was further scrutinized by spectroscopic analysis and theoretical calculations. Our findings have illuminated the roles of surface sites in the solid-phase adsorption of HREEs from acidic solutions.
摘要:
我们研究了重稀土元素(HREE,Yb)来自使用MCM-22沸石的酸性溶液,既是层状合成粘土模拟物,又是研究HREE在铝硅酸盐材料上吸附机理的新平台。机理研究表明,Yb(III)在表面吸附位点的吸附主要通过该位点与Yb(III)物种之间的静电相互作用发生。Yb吸附对溶液pH值的依赖性表明了表面电荷的作用,骨架Al的含量表明布朗斯台德酸位点(BAS)参与了Yb(III)离子的吸附,通过光谱分析和理论计算进一步审查。我们的发现阐明了表面位点在酸性溶液中HREE固相吸附中的作用。