Catalysis by Metal Organic Frameworks: Perspective and Suggestions for Future Research

Abstract

Metal organic frameworks (MOFs) have drawn wide attention as potential catalysts, offering high densities of catalytic sites in high-area porous solids, some with stabilities at high temperatures. The field is at an early stage, characterized by numerous discoveries and novel demonstrations of catalytic properties associated with the crystalline structures of MOFs, but applications of MOFs as catalysts are still lacking. In this perspective we summarize advantages and limitations of MOFs as catalysts and fundamental issues to be addressed about their potential applications. MOF framework compositions and pore structures can strongly influence catalytic performance, allowing, for example, shape-selective and bifunctional catalysis, but research is needed to quantify reaction/transport processes in MOFs, identify catalytic sites, and determine intrinsic catalytic reaction rates. Progress is hindered by the lack of understanding of the heterogeneity of MOFs, with catalytic sites sometimes being in structures such as defects not determined by X-ray diffraction crystallography. Determination of the dynamics of MOFs and their catalytic sites, as well as the intrinsic kinetics of catalytic reactions, will help to advance guidelines for synthesizing optimum catalysts. Further, MOFs present challenges related to stability and regeneration as catalysts, some associated with the unique nature of MOFs, such as the node–linker bonds, which can break during catalysis. There are opportunities to understand these matters in depth and to find conditions of catalytic operation that minimize the processes leading to deactivation.

Copper(II) Oxide Nanoparticles Impregnated on Melamine‐Modified UiO‐66‐NH2 Metal–Organic Framework for C–N Cross‐Coupling Reaction and Synthesis of 2‐Substituted Benzimidazoles

“…Consequently, MOFs provide many advantages (e.g. large pore size for easy and fast mass transfer, shape selective for reactants, and confinement effect for encapsulation of the catalyst species) as supports for catalysis in comparison with inorganic porous materials.…”

Metal–Organic Framework Thin Films: Fabrication, Modification, and Patterning

“…In contrast to other porous materials, MOFs also possess designable structures that can be engineered with tailored pores for selective adsorption of specific gases [1]. Moreover, MOFs show outstanding features as in structural flexibility, thermal and chemical stability, etc., which grant MOFs great potential in numerous applications, such as gas storage and separation [2][3][4][5], liquid purification [6][7][8][9], catalysis [10][11][12][13], gas/chemical sensing [14][15][16][17][18], and energy production [19][20][21][22]. Other than direct applications, MOFs have also been used as precursors/templates for the production of inorganic functional materials with unique designability [23].…”

Restricting Polyoxometalate Movement Within Metal-Organic Frameworks to Assess the Role of Residual Water in Catalytic Thioether Oxidation Using These Dynamic Composites

“…For this reason, metal-organic frameworks (MOFs) with a high degree of tunability are attractive support materials (Vermoortele et al, 2012;Vandichel et al, 2015;Liu et al, 2018;Palmer et al, 2018). Constructed from metal or metal cluster nodes linked via multitopic organic ligands, MOFs are an increasing popular class of designer materials due to the ability to obtain highly crystalline, porous, and stable structures (Yaghi et al, 2003;Kitagawa et al, 2004;Furukawa et al, 2013;Jiao et al, 2018;Chen et al, 2019;Yang and Gates, 2019).…”