Creation of Exclusive Artificial Cluster Defects by Selective Metal Removal in the (Zn, Zr) Mixed-Metal UiO-66
Xiao Feng, Himanshu Sekhar Jena, Chidharth Krishnaraj, Daniel Arenas Esteban, Karen Leus, Guangbo Wang, Jiamin Sun, Martina Rüscher, Janis Timoshenko, Beatriz Roldán Cuenya, Sara Bals, Pascal Van Der Voort
Abstract
The differentiation between missing linker defects and missing cluster defects in MOFs is difficult, thereby limiting the ability to correlate materials properties to a specific type of defects. Herein, we present a novel and easy synthesis strategy for the creation of solely “missing cluster defects” by preparing mixed-metal (Zn, Zr)-UiO-66 followed by a gentle acid wash to remove the Zn nodes. The resulting material has the reo UiO-66 structure, typical for well-defined missing cluster defects. The missing clusters are thoroughly characterized, including low-pressure Ar-sorption, iDPC-STEM at a low dose (1.5 pA), and XANES/EXAFS analysis. We show that the missing cluster UiO-66 has a negligible number of missing linkers. We show the performance of the missing cluster UiO-66 in CO2 sorption and heterogeneous catalysis.