It has been acknowledged that small size could arouse revolutionary effects especially in catalysis. In recent years, MOFs has been accepted as a promising candidate in gas catalysis. However, reviewing back to the past decade, bulk MOFs have been earning intensive research interest whose particle size normally fall into the range of 50μm to 300μm, while cases to investigate the small size effects to MOFs are very rare. Cu3(BTC)2 is a kind of typical metal-organic frameworks. In this work, we report a simple preparation method of nano-MOFs taking (Cu3(BTC)2) as the example. Via further pyrolysis process, we also obtained the CeO2 tubes supported nano-CuO clusters catalysts. It is believed that both of the CeO2 tubes supported nano-Cu-MOFs and the CeO2 tubes supported nano-CuO will perform great potential catalytic properties. More importantly, this work develop an alternative approach to synthesis composites of nano-MOF or nano-MOx /supporting materials. According to the results, a great deal of nano-scale MOFs will quickly nucleate and grow within the CeO2 tubes after immersing the substrate with CeO2 nanotubes into the aqueous solution of the metal and organic mixtures. Both of DMF and ethanol were used as solvents. For the system with solvents of DMF, it is observed that the cavities of ceria tubes have been filled with some well defined geometry at the reaction time of 20min. With the reaction time going on, we also notice that most of the ceria tubes broke and dissolved, leaving a stack of small crystals with the average size of 1.5μm. With disappearance of ceria tubes, large amount of nano-sized crystals were exposed as expectedly. X-Ray indicates that all the peaks could be readily indexed to the Cu3(BTC)2(H2O)3.xH2O. The size of the prepared nano-MOFs falls into the range of 100nm to 500nm. Similar process happened in the system with ethanol as solvents, but the reaction rate in ethanol is rather quicker than that in DMF. As a result, the formation of MOFs and dissolution of ceria tubes could accomplished in 15min, while the whole process needs 35min in DMF. Accordingly, the size of the MOFs obtained in ethanol is a little smaller and the crystallinity is weaker than the ones prepared in DMF. Notably, after annealing the nano-CuO MOFs in air, we can also obtain nano-CuO particle clusters which uniformly distribute at the innerface of the ceria tubes. It is believed the ceria tubes supported nano-CuO composites will perform great catalytic properties.

Nano-confinement preparations of nano- CuO-MOFs in ceria tubes

253rd National Meeting (2017)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.