用于氙氪吸附分离的金属-有机骨架材料耐辐照性能的初步研究  

Preliminary study on irradiation stability of metal-organic skeleton materials for the adsorption and separation of xenon and krypton

作　　者：陈彬[1] 武山[1] 宋晓靓[1] 马和平 CHEN Bin;WU Shan;SONG Xiaojing;MA Heping(Northwest Institute of Nuclear Technology,Xi'an 710024,China;Xi'an Jiaotong University,Xi'an 710049,China)

机构地区：[1]西北核技术研究所,西安710024 [2]西安交通大学,西安710049

出　　处：《核技术》2022年第1期49-55,共7页Nuclear Techniques

基　　金：中国原子能科学研究院核数据重点实验室开放基金项目(No.2021201C151)资助。

摘　　要：由于乏燃料后处理废气中放射性氙(Xenon,Xe)和氪(Krypton,Kr)的去除需求以及高纯度Xe气体的商业价值,Xe和Kr的吸附分离越来越受到重视。目前Xe/Kr的分离主要采用能源和资本密集型的低温精馏法。以金属-有机骨架材料为吸附剂的多孔材料已经展示出在相对较高温度下选择性吸附Xe和Kr的能力,有望替代低温精馏法实现低成本的Xe/Kr分离。实验研究了三种热稳定性良好的金属-有机骨架材料(Co/DOBDC、Ni/DOBDC、Co_(3)(HCOO)_(6))对Xe和Kr的吸附分离性能。从材料在273 K温度下对Xe和Kr的吸附等温线、亨利常数、亨利选择性和理想吸附溶液理论(Ideal Adsorbed Solution Theory,IAST)选择性等测试和计算结果来看,Co/DOBDC和Ni/DOBDC在常压下对Xe具有较大的吸附容量,适用于Xe吸附存储的应用场景;Co_(3)(HCOO)_(6)在低压吸附下具有大的Xe亨利常数、Xe/Kr亨利选择性和Xe/Kr IAST选择性,适用于Xe和Kr吸附分离的应用场景。通过对Co/DOBDC、Ni/DOBDC和Co_(3)(HCOO)_(6)的γ射线辐照稳定性进行了研究,比较材料辐照前后的孔性质(比表面积和孔容)可知,Co/DOBDC和Ni/DOBDC经不同剂量的γ射线辐照后其各自的孔性质均发生了明显的变化,而且Co/DOBDC的孔性质变化程度较Ni/DOBDC的大,而Co_(3)(HCOO)_(6)经总剂量9 kGy的γ射线辐照后其孔性质基本没有变化,表明Co_(3)(HCOO)_(6)具有在辐射场景下的应用潜力。[Background]The adsorption and separation of Xenon(Xe)/Krypton(Kr)has received increasing attention due to the concern of reprocessing radioactive isotopes of Xe and Kr from off-gas of used nuclear fuel as well as the commercial value of high purity Xe gas.At present,the separation of Xe/Kr is mainly through cryogenic distillation,which is energy and capital intensive.Porous materials such as metal-organic frameworks(MOFs)have shown the ability to selectively adsorb xenon and krypton at relative high temperature,hence are expected to replace cryogenic distillation to achieve low-cost Xe/Kr separation.[Purpose]This study aims to investigate the gamma radiation stability of three MOFs(Co/DOBDC,Ni/DOBDC,Co_(3)(HCOO)_(6))used for Xe and Kr adsorption separation.[Methods]First of all,three MOFs,i.e.,Co/DOBDC,Ni/DOBDC,and Co_(3)(HCOO)_(6),were synthesized and activated according to the preparation methods in the published literature,and the adsorption isotherms of Xe and Kr in three MOFs samples were measured by using physical adsorption instrument with a specially designed water circulating system to maintain a constant temperature(273 K).Then,these samples were irradiated withγ-ray(1.322 MeV)at a gamma dose rate of 0~1 kGy·h;at ambient temperature.Samples’properties,such as Henry constant,Henry selectivity and ideal adsorbed solution theory(IAST)selectivity of Xe/Kr,before and after irradiation,were characterized by X-ray diffraction(XRD)patterns and N;adsorption measurements.Finally,theγ-ray radiation stability of Co/DOBDC,Ni/DOBDC and Co_(3)(HCOO)_(6)were studied,and the pore properties(specific surface area and pore volume)before and after irradiation were compared.[Results&Conclusions]Experimental results from the observed single-component Xe and Kr isotherms,Henry’s constants,Henry’s constant ratio and IAST selectivity of the sample,show that Co/DOBDC and Ni/DOBDC as adsorbents have the potential to adsorb and storage high concentration Xe whilst Co_(3)(HCOO)_(6)has the potential for adsorption separati

关 键 词：金属-有机骨架材料 Xe和Kr 吸附分离 Γ射线辐照 

分 类 号：TL99[核科学技术—核技术及应用] O647.3[理学—物理化学]