MOFs‐Based Heterogeneous Catalysts: New Opportunities for Energy‐Related CO₂ Conversion

Abstract

www.advancedsciencenews.comreaction is more unfavorable. [22,23] Comparing to the researches on artificial H 2 production, the knowledge referring to efficient and selective reduction of CO 2 to energy-rich molecules is urgent to be updated. CO 2 conversion is often traced back to 1972 that reported by Honda and Fujishima with using inorganic photocatalysts TiO 2 . [24] As the capture of CO 2 has already been studied in metal-organic frameworks (MOFs), [25][26][27][28] it has recently been studied for their use as catalysts for the reduction of CO 2 into high-value chemicals. [14,29] MOFs hold great promise for applications in the field of CO 2 reduction, which can act directly as the catalysts or as components to promote CO 2 reduction in a hybrid catalytic system. The interior of MOFs can be designed to have open metal sites, specific heteroatoms, functionalized organic ligand, other building unit interactions, hydrophobicity, defects, porosity, and embedded nanoscale metal catalysts which is crucial for the development of better CO 2 reduction performance MOFs. [30][31][32] Due to the poor electron conductivity of MOFs, [33,34] and the inaccessibility of all the catalytic active sites to the reactants, the stability of MOFs in water and under UV light irradiation need to be further improved. We believe that a comprehensive and up-to-date review summarizing the recent applications of MOFs for CO 2 reduction will contribute to improve theoretical understanding of this field. In order to make a better achievement, it is necessary to use the MOF to build more complex materials to address CO 2 capacity and reduction ability together in one material. Future MOFs materials for CO 2 reduction should be economical and environmental friendly. The keys for promoting catalysis include structural defects in the MOFs, open metal sites from metal clusters, Lewis acid sites from the metal cluster and organometallic linker, and cocatalyst functionalized MOFs.Several reviews focusing on MOFs for CO 2 conversion have been recently reviewed and discussed. Dhakshinamoorthy et al. pointed out that photoexcitation of the light absorbing units in MOFs often generates a ligand-to-metal charge-separation state that can result in photocatalytic activity. Maina et al. discussed the corelationship between the properties of MOF materials including their CO 2 reduction catalytic performance under different reaction conditions. Li and co-workers have summarized the recent applications of MOFs for photocatalytic CO 2 reduction, in which MOFs can act as the photocatalysts for CO 2 reduction or as components in a hybrid photocatalytic system to promote CO 2 reduction. Yaghi and co-workers also pointed out that the challenge in developing catalysts for CO 2 photo-or electroreduction is rooted in the interplay between selectivity, activity, and efficiency. [35][36][37][38] Synthetic Approaches for MOFsMOFs, also called porous coordination polymers, are extended framework with open structures constructed from metal ions and organic ligands linked...

Hybrid Catalysts for CO2 Conversion into Cyclic Carbonates

“…By varying the combination of the selected OL/SBU, as well as the synthesis conditions, different crystalline porous networks can be obtained [63,64]. These solids possess a series of interesting features such as extremely high specific surface area, large pore volume, ordered three-dimensional (3D) structure and elevated adsorption properties, making them interesting candidates for applications in materials science [65][66][67][68]. Some examples of MOF systems, together with their specific surface areas, are reported in Figure 2 All the abovementioned characteristics, together with the possibility of fine-tuning the metal organic architecture, allow explaining the use of MOF structures in fields ranging from gas adsorption and storage to drug delivery, magnetism, and luminescence, among others.…”

Metal-organic frameworks for electrochemical reduction of carbon dioxide: The role of metal centers

“…Furthermore, their physical and chemical properties can be regulated by tuning the composition, metal node and organic ligand at the molecular level. These advantages make them attractive porous materials for application in gas capture and separation, heterogeneous catalysis, sensing and drug delivery [60][61][62][63][64][65] . Especially, MOF-based materials have attracted growing interests in the field of energy conversion and storage including photo-and electrocatalytic water splitting, and CO 2 reduction [36,38,59,[66][67][68][69][70] .…”

“…In this review, we have systematically summarized current progress of MOF-based materials for electrocatalysis reduction of CO 2 . Although a few of reviews have described MOFs for photoand electro-catalytic CO 2 conversion [43][44][45][60][61][62][75][76][77][78] , these reviews mainly focused on the pristine MOFs for reduction of CO 2 . We mainly focus on discussing the recent progresses of MOF composites (e.g.…”

Carbon‐Modified CuO/ZnO Catalyst with High Oxygen Vacancy for CO2 Hydrogenation to Methanol

“…Metal‐organic frameworks (MOFs) are prospective materials for catalysis due to its porous and caged characteristics with both open metal sites and functionalized organic ligand . In the meantime, more and more researchers began to apply MOF‐derived materials to catalysis, and researches show that the derivatives of MOFs have exciting opportunities in the conversion and utilization of CO 2 . As for hydrogenation of CO 2 to methanol, ZIF‐8 (as a Zn‐based MOF and the theoretical formula is C 8 H 12 N 4 Zn) has been first used directly as the carrier of copper‐based catalysts, but results show that only when Zn element exists in the form of oxide it can catalyze CO 2 hydrogenation to methanol with copper .…”