Metal–Organic Frameworks and Metal–Organic Framework-Derived N-Doped Porous Carbon Materials as Heterogeneous Catalysts: Chemical Fixation of Carbon Dioxide under Mild Conditions and Electrochemical Hydrogen Evolution

Abstract

Two flexible tetracarboxylic acids with ether (H 4 AOIA) and amine (H 4 ANIA) linkages have been employed for the formation of two distinct Co-metal−organic frameworks (MOFs) with diverse architectures. Both the MOFs were shown to demonstrate remarkable catalytic activities for the chemical conversion of CO 2 into cyclic carbonates under ambient reaction conditions with considerably high turnover number values. Further, carbonization of the two-dimensional-MOF, Co-ANIA, under inert atmospheric conditions at a temperature of 800 °C resulted in the formation of cobalt containing N-doped nanocomposite (Co@ NPC2). In the context of generation of a sustainable source of energy and to carry out successive conversions, the singlecomponent nanocomposite, Co@NPC2, was shown to act as an efficient cost-effective non-noble metal electrocatalyst through its electrochemical activity toward hydrogen evolution.

Graphene-Templated Cobalt Nanoparticle Embedded Nitrogen-Doped Carbon Nanotubes for Efficient Visible-Light Photocatalysis

“…Recently, metal–organic frameworks (MOFs), consisting of inorganic metal ions and organic ligands, have been used as effective templates for the generation of metal/metal oxide decorated porous carbons. , MOFs exhibit attractive features such as tunable morphology and functionality, ultrahigh surface area, and a well-ordered structure, which make MOFs efficient candidates for sustainable energy and environmental remediation, gas storage, drug delivery, energy conversion, light harvesting, and sensing applications. ,,− More importantly, a kind of subclass of MOFs, zeolite-imidazolate frameworks (ZIFs), containing a divalent transition-metal ion coordinated through the N atom of the imidazole ring have attracted immense interest toward photocatalytic activity owing to their excellent specific surface area, higher thermal and chemical stability, good magnetic properties, tunable zeolite topologies, and high affinity toward organic molecules. − The enriched nitrogen moieties in ZIFs act as an effective electron donor system for photocatalytic reactions, which enhances the catalytic efficiency by increasing the visible-light harvesting capacity. , Among the various ZIFs, ZIF-67 is found to be an ideal candidate for photocatalytic dye degradation owing to its excellent properties such as exciting electrical conductivity, promising chemical stability, high surface area, high cyclic reusability, and high graphitization degree. − Moreover, the presence of Co nanoparticles along with nitrogen-doped carbon helps to promote the photocatalytic performance. Importantly, its facile green synthetic approach has highly motivated researchers toward the sustainable degradation of organic dyes .…”

“…Recently, metal−organic frameworks (MOFs), consisting of inorganic metal ions and organic ligands, have been used as effective templates for the generation of metal/metal oxide decorated porous carbons. 21,22 MOFs exhibit attractive features such as tunable morphology and functionality, ultrahigh surface area, and a well-ordered structure, which make MOFs efficient candidates for sustainable energy and environmental remediation, gas storage, drug delivery, energy conversion, light harvesting, and sensing applications. 5,12,21−23 More importantly, a kind of subclass of MOFs, zeoliteimidazolate frameworks (ZIFs), containing a divalent transition-metal ion coordinated through the N atom of the imidazole ring have attracted immense interest toward photocatalytic activity owing to their excellent specific surface area, higher thermal and chemical stability, good magnetic properties, tunable zeolite topologies, and high affinity toward organic molecules.…”

Chemical Fixation of CO2 Under Solvent and Co-Catalyst-free Conditions Using a Highly Porous Two-fold Interpenetrated Cu(II)-Metal–Organic Framework

“…Therefore, chemical fixation of CO 2 into fine chemicals catalyzed by cost-effective, environmentally friendly catalysts has gained significant interest. , In this regard, the coupling of carbon dioxide with epoxides to generate cyclic carbonates has attracted significant interest owing to its 100% atom economic nature. , Further, the resulting product, i.e., cyclic carbonates, offer various potential applications in the production of polymers, as electrolytes, and so on. − Several homogeneous catalysts such as quaternary phosphonium or ammonium salts, − ionic liquids, Lewis acids and bases, transition metal complexes, − etc. have been employed for cyclization of CO 2 with various epoxides at ambient conditions. , However, to overcome the drawbacks of catalyst recycling associated with homogeneous catalysts, several heterogeneous catalysts have been developed for the cyclization of CO 2 with various epoxides. − However, the majority of the catalytic systems reported for cycloaddition of carbon dioxide require additional co-catalysts such as tetra- n -butylammonium bromide, ( n- Bu 4 NBr) to obtain a good yield of cyclic carbonates. − For large-scale sustainable production of cyclic carbonates under green, environmentally friendly conditions, it is essential to overcome the use of co-catalysts. In this regard, the design of new MOF-based heterogeneous catalysts capable of catalyzing the conversion of CO 2 into cyclic carbonates at solvent- and co-catalyst-free conditions is highly desired.…”

Transition Metal Ions Regulated Structural and Catalytic Behaviors of Coordination Polymers

“…Considerable efforts have been devoted to preparing an organic ligand with versatile coordination sites to promote the construction of higher dimensional, robust, and emerging multifunctional framework materials. In this perspective, coordination polymers (CPs) and metal–organic frameworks (MOFs) are the most prominent outcomes with porous crystalline nature, lowest framework density, and inorganic nodes constituted by metal ions/clusters coordinated with organic moieties containing at least two requisite binding sites. − Such polymeric frameworks have become the center of attraction for researchers to carry out diverse applications in selective gas storage and gas adsorption, − ion-exchange, − separation, − conductivity, − drug delivery, − sensor devices, − and various catalysis like autocatalysis, biocatalysis, photocatalysis, organo-catalysis, along with electrocatalysis. − At present, a large number of metal centered catalysts are available for Lewis-acid-based catalytic transformations in well-known reactions like cyanosilylation, − Diels–Alder, Ene reaction, aldol reaction, , ketalization, etc. − In several catalytic reactions, CPs/MOFs work effectively as precatalysts, cocatalysts, cooperative catalysts, and promoters to accelerate the formation of valuable products for large scale applications. The catalytic activities of CPs/MOFs alter due to the number of donor sites in organic ligands, available functional groups in ligands such as basic (NH 2 ) and acidic groups (OH and SO 3 H), oxidation states of metals or metal-clusters, ionic sizes, shapes, and geometries of complexes .…”