Molecular Scalpel to Chemically Cleave Metal–Organic Frameworks for Induced Phase Transition

Abstract

A bottom-up chemical synthesis of metal–organic frameworks (MOFs) permits significant structural diversity because of various combinations of metal centers and different organic linkers. However, fabrication generally complies with the classic hard and soft acids and bases (HSAB) theory. This restricts direct synthesis of desired MOFs with converse Lewis type of metal ions and ligands. Here we present a top-down strategy to break this limitation via the structural cleavage of MOFs to trigger a phase transition using a novel “molecular scalpel”. A conventional CuBDC MOF (BDC = 1,4-benzenedicarboxylate) prepared from a hard acid (Cu2+) metal and a hard base ligand was chemically cleaved by l-ascorbic acid acting as chemical scalpel to fabricate a new Cu2BDC structure composed of a soft acid (Cu1+) and a hard base (BDC). Controlled phase transition was achieved by a series of redox steps to regulate the chemical state and coordination number of Cu ions, resulting in a significant change in chemical composition and catalytic activity. Mechanistic insights into structural cleavage and rearrangement are elaborated in detail. We show this novel strategy can be extended to general Cu-based MOFs and supramolecules for nanoscopic casting of unique architectures from existing ones.

Customizing the microenvironment of CO2 electrocatalysis via three‐phase interface engineering

“…Consequently, researchers focus on the development of various catalysts with high activity. [9][10][11] Similarly, substantial efforts have been invested in the fabrication of different CRR catalysts, including single-atom, 12 alloy, 13,14 surface oxidation state, [15][16][17] grain boundaries, 18 solid solutions, 19 morphologies, 20,21 chemical composition, 22 and crystal facet engineering. 23 Nevertheless, differently to thermal catalysis, since CRR occurs on a gas/solid/liquid three-phase interface (Figure 1C), 24 its reactivity is also sensitive to the local reaction environment of the catalysts, such as the specific electrolyte, 25 pH, 26 presence of metal cations, 27 surface structure and composition of the catalyst, 28 and some other factors.…”

Hollow terbium metal–organic-framework spheres: preparation and their performance in Fe3+ detection

“…These results indicate that the carboxylic groups of H 3 BTC are dehydrogenated and then coordinated with Tb 3+ ions in Tb-MOF. 22 The difference between ν as (COO − ) and ν s (COO − ) value is 192 cm −1 (or 193 cm −1 ), which implies that three coordinate modes, monodentate, chelation and bridging exist in the synthesized Tb-MOF. 22 …”

“… 22 The difference between ν as (COO − ) and ν s (COO − ) value is 192 cm −1 (or 193 cm −1 ), which implies that three coordinate modes, monodentate, chelation and bridging exist in the synthesized Tb-MOF. 22 …”

Toward High‐Performance CO2‐to‐C2 Electroreduction via Linker Tuning on MOF‐Derived Catalysts

“…Main eCO 2 RR products were identified as CO at low current density and C 2 H 4 at high current density. For the NH 2 -Cu-BDC and OH-Cu-BDC [2,12,[27][28][29][30][31][32][33] (Table S1, Supporting Information). Black square for the results in the literature.…”