A precise and scalable post-modification of mesoporous metal-organic framework NU-1000 via atomic layer deposition

The connectivity of NU-1000, a metal-organic framework, gives rise to Zr₆ nodes with hydroxyl-containing functional groups pointing into the large 1D mesoporous hexagonal channels of the framework. These free and exposed-OH groups are ideal grafting sites, and they can be easily tailored to serve a specific function. Through atomic layer deposition in MOFs (AIM), we demonstrate the ability to form several oxides with atomic precision at the exposed-OH sites of NU-1000. Importantly, this process occurs without changing the overall structure of the framework. Recent progress in scaling AIM process of the ultrahigh surface area (2300 m²/g) framework as well as progress in pinpointing the location and mechanism of surface chemical reactions of catalytically relevant metals is discussed. Computational, synchrotron, and in-situ analytical methods including DFT, differential electron diffraction, and in situ FTIR are brought to bear on several new metal systems, many of which show remarkably self-limiting behavior.