高比表面积水滑石材料的宏量制备及吸附性能研究
发布时间:2018-05-20 22:19
本文选题:水滑石 + 丙酮处理 ; 参考:《北京化工大学》2015年硕士论文
【摘要】:层状双金属氢氧化物(简称水滑石或LDHs)是一类新型无机二维纳米材料,在阻燃抑烟、PVC热稳定剂、红外吸收、紫外阻隔、催化、电化学储能等领域已经取得了工业化应用或表现出很好的应用前景。普通水滑石(Normal LDHs,简称N-LDHs)比表面积较小,大约为10~50 m2/g,一定程度上限制了水滑石及水滑石基复合材料的应用,尤其是在催化、吸附、电化学储能等领域。本论文采用有机溶剂丙酮处理(Acetone Treatment,简称AT)的方法,制备四种水滑石AT-Mg2Al-CO3-LDHs、AT-Ni2Al-CO3-LDHs、 AT-Zn2Al-CO3-LDHs和AT-Mg3Al-CO3-LDHs,通过优化制备条件,其最大比表面积分别为123.5 m2/g、254.7 m2/g、54.5 m2/g和195.0 m2/g,考虑到AT-Mg3Al-CO3-LDHs的低成本及低毒性,且不会对环境产生二次污染等优点,故本论文研究了AT-Mg3Al-LDHs的焙烧产物AT-Mg3Al-LDO对不同浓度重铬酸钾(K2Cr207)溶液中重金属铬Cr(Ⅵ)的吸附性能,通过ICP-AES表征技术,测得其吸附容量可达到55.91mg/g,约180 min可达吸附平衡,吸附容量是普通水滑石焙烧产物(简称N-LDO)吸附容量(23.71 mg/g)的~2.4倍,吸附平衡时间为N-LDO(1080 min)的1/6,吸附效率显著提升。进一步研究了丙酮处理法的工程技术问题,将高比表面积AT-Mg3Al-CO3-LDHs的制备进行了放大,通过中型反应釜装置、陶瓷膜等中试设备,实现了高比表面积水滑石材料的宏量制备,成功制备约2.7 Kg高比表面积AT-Mg3Al-CO3-LDHs,并对样品进行了一系列表征,从XRD、SEM表征结果可以看出与小试实验所制备的高比表面积水滑石结构和形貌保持一致,BET表征证明AT-Mg3Al-CO3-LDHs存在丰富的介孔结构,比表面积达到174.5 m2/g,为高比表面积水滑石材料的工业化生产提供了实践探索。
[Abstract]:Layered bimetallic hydroxides (short for hydrotalcite or LDHs) are a new kind of inorganic two-dimensional nano-materials, which are used as flame retardant and smoke suppressant for PVC heat stabilizer, infrared absorption, ultraviolet barrier, catalysis, etc. Electrochemical energy storage and other fields have been industrialized applications or show good application prospects. The specific surface area of normal LDHs (N-LDHs) is small, about 1050m2 / g, which limits the application of hydrotalcite and hydrotalcite matrix composites, especially in the fields of catalysis, adsorption, electrochemical energy storage and so on. In this paper, four kinds of hydrotalcite AT-Mg2Al-CO3-LDHs, AT-Zn2Al-CO3-LDHs and AT-Mg3Al-CO3-LDHswere prepared by using organic solvent acetone treatment method. The maximum specific surface area of AT-Mg2Al-CO3-LDHswas 123.5 m2g254.7 m2g54.5m2g and 195.0 m2grespectively, considering the low cost and low toxicity of AT-Mg3Al-CO3-LDHs. Therefore, the adsorption properties of AT-Mg3Al-LDO, a roasting product of AT-Mg3Al-LDHs, for heavy metal Cr (鈪,
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