论文标题
Zn-Al LDH与腐蚀相关物种插入的原位动力学研究
In situ kinetics studies of Zn-Al LDH intercalation with corrosion related species
论文作者
论文摘要
三个阴离子交换反应的动力学参数-Zn-LDH-NO3-Zn-LDH-CL，Zn-LDH-NO3-Zn-LDH-SO4和Zn-LDH-NO3-Zn-LDH-NO3-Zn-LDH-VOX-通过原位同步研究获得。第一个和第二个是两个阶段的反应。第一阶段的特征是减速成核后的二维扩散控制反应，第二阶段是一维扩散控制反应，也具有减速核定效应。在交换NO3 -CL宿主阴离子的情况下，完全释放出来，而在NO3 -SO42的情况下，反应在没有完全释放的硝酸盐阴离子的情况下结束。 Zn-LDH-NO3-Zn-LDH-VOX的交换是一阶段反应，比前两种情况慢得多。在这种情况下，它的特征是一个一级二维反应和成核被认为是瞬时的。结果，在此过程结束时，有两个具有不同聚瓦酯物质的晶相，大概是V4O124和V2O74，硝酸盐阴离子尚未完全释放。宾客代替第3阴离子的速率可以表示为Cl> so42> voxy。
Kinetics parameters for three anion exchange reactions - Zn-LDH-NO3 - Zn-LDH-Cl, Zn-LDH-NO3 - Zn-LDH-SO4 and Zn-LDH-NO3 - Zn-LDH-VOx - were obtained by in situ synchrotron study. The first and the second ones are two-stage reactions; the first stage is characterized by the two-dimensional diffusion-controlled reaction following deceleratory nucleation and the second stage is a one-dimensional diffusion-controlled reaction also with a decelerator nucleation effect. In the case of exchange NO3 - Cl host anions are completely released, while in the case of NO3 - SO42 the reaction ends without complete release of nitrate anions. The exchange of Zn-LDH-NO3 - Zn-LDH-VOx is one-stage reaction and goes much slower than the previous two cases. It is characterized by a one stage two-dimensional reaction and nucleation considered to be instantaneous in this case. As a result, at the end of this process there are two crystalline phases with different polyvanadate species, presumably V4O124 and V2O74, nitrate anions were not completely released. The rate of replacing NO3 anions by guest ones can be represented as Cl > SO42 > VOxy.
