Hf‐based Metal‐Organic Frameworks in Heterogeneous Catalysis

Abstract

Among the large family of metal-organic frameworks (MOFs), Hf-based MOFs are foreseen as promising materials for practical applications due to their exceptional characteristics such as rich structure versatility and outstanding stability. This review discusses catalytic applications of Hf-MOFs since their development in 2012, and are summarized according to the location of the active site: at the hafnium node, at the linker or as a single-site chemical entity located at the hafnium node after post-synthetic functionalization. Special emphasis is made to synthetic preparation methods and catalytic performance.

Tailoring Lewis/Brønsted acid properties of MOF nodes via hydrothermal and solvothermal synthesis: simple approach with exceptional catalytic implications

“…On the other hand, the oxide ring-opening reaction (see Scheme 2) has been employed as a model catalytic test to distinguish catalytic Brønsted acid sites. 16,56,57 Considering this, Hf-MOF-808_H 2 O and Hf-MOF-808_DMF have been tested for the styrene oxide ring-opening reaction with isopropanol (see the experimental section for details).…”

Coordinatively Unsaturated Hf-MOF-808 Prepared via Hydrothermal Synthesis as a Bifunctional Catalyst for the Tandem N-Alkylation of Amines with Benzyl Alcohol

“… 29 It is worth noting that, in the last years, Zr- and Hf-MOFs have shown exceptional thermal, mechanical, and chemical stabilities, 32 − 34 allowing their application as active and stable catalysts for a wide range of chemical processes. 35 − 40 …”

Heterogeneous nanozymatic activity of Hf oxo-clusters embedded in a metal–organic framework towards peptide bond hydrolysis

“…32 Intrigued by this unique dual Lewis/Bronsted acidity of Hf(IV) oxo-clusters which seem to directly impacts the reactivity, and the potential of Zr-MOF materials as heterogeneous proteolytic agents, in this work we set out to develop the proteolytic activity of the Hf-NU-1000 MOF given that Hf6O8-based MOFs (Hf-MOFs) have been much less explored in catalysis than their Zr counterparts. [33][34][35] In contrast to the discrete nature of Hf 18 cluster we studied previously, the Hf oxo-clusters [Hf6(µ3-O)4(µ3-OH)4(H2O)4(OH)4] 8+ which constitute Hf-NU-1000 MOF are connected by organic ligands resulting in the extended porous material. Thus, in addition to further developing Hf-based nanozymes as site-selective proteolytic agents, this study provides comparative insights into the nanozymatic activities of discrete and MOF-embedded Hf oxo-clusters.…”