MOFs for the capture of radionuclides

Speaker: Prof. Christophe VOLKRINGER

Time: Thursday, 2018.07.26, am 10:00

Location: First floor conference room, 402, Dushu Lake Campus

 

Abstract

Since their discovery, porous Metal-Organic Frameworks (MOFs) were investigated for many potential applications in various domains like catalysis, gas storage, optics or medicine… Few years ago, nuclear energy technology remained still one of the last important industries without connexion with the MOFs field and not taking advantage of their original chemistry and their large porosity. In our laboratory, we are developing different approaches involving MOFs in order two fill this gap. This communication will be devoted to the use of MOF for the capture of radionuclides in the case of a nuclear accident.

 

Prototypical MOFs (MIL-n, UiO-66, ZIF-8…) were used for the capture of radioactive molecules generated during a nuclear accident like iodine derivatives (I2, CH3I), actinides (U, Th) or gaseous ruthenium (RuO4). In each case, the MOF compounds exhibit very high sorption capacities, modulated by the size of the pores and the functionalization of the framework.

 

The resistance of MOFs under drastic conditions (gamma ray irradiation, water, high temperature) will be also discussed. One of the most impressive result was the stability of aluminium based MOFs for an irradiation dose of 2 MGy, comparable to at least 8 days under strong radioactive conditions occurring in a nuclear accident. Furthermore, it is widely admitted that MOFs are water sensitive and that high temperatures accelerate the hydrolysis phenomena and the collapse of the porous network. We have investigated the resistance of the prototypical HKUST-1 MOF under steam flow at temperatures ranging from RT to 200°C. Surprisingly, the porous framework is not degraded at 200°C, whereas temperatures close to 100°C lead to the total destruction of the MOF.