Mixed‐Metal MOF‐74 Templated Catalysts for Efficient Carbon Dioxide Capture and Methanation

Abstract

The vast chemical and structural tunability of metal–organic frameworks (MOFs) are beginning to be harnessed as functional supports for catalytic nanoparticles spanning a range of applications. However, a lack of straightforward methods for producing nanoparticle‐encapsulated MOFs as efficient heterogeneous catalysts limits their usage. Herein, a mixed‐metal MOF, NiMg‐MOF‐74, is utilized as a template to disperse small Ni nanoclusters throughout the parent MOF. By exploiting the difference in NiO and MgO coordination bond strength, Ni2+ is selectively reduced to form highly dispersed Ni nanoclusters constrained by the parent MOF pore diameter, while Mg2+ remains coordinated in the framework. By varying the ratio of Ni to Mg in the parent MOF, accessible surface area and crystallinity can be tuned upon thermal treatment, influencing CO2 adsorption capacity and hydrogenation selectivity. The resulting Ni nanoclusters prove to be an active catalyst for CO2 methanation and are examined using extended X‐ray absorption fine structure and X‐ray photoelectron spectroscopy. By preserving a segment of the Mg2+‐containing MOF framework, the composite system retains a portion of its CO2 adsorption capacity while continuing to deliver catalytic activity. The approach is thus critical for designing materials that can bridge the gap between carbon capture and CO2 utilization.

Molecular Stabilization of Sub‐Nanometer Cu Clusters for Selective CO2 Electromethanation

“…[21][22][23] These processing steps result in loss of organic linkers that offer the ability to confine the size and tune the electronic properties of nanocrystals grown inside the MOFs. [24][25][26] We posit that if we were able to devise a method to construct nanomaterials from MOFs while keeping the organic linker unaltered, we would have the opportunity to use it to stabilize the as-formed active sites under CO2RR operating conditions. Herein, we report an electrochemical oxidation-reduction (EOR) approach for the preparation of sub-nanometer Cu clusters from Cu-based MOFs that retains the organic linkers for highly selective and durable electrosynthesis of methane during CO2RR.…”

“…[21][22][23] These processing steps result in loss of organic linkers that offer the ability to confine the size and tune the electronic properties of nanocrystals grown inside the MOFs. [24][25][26] We posit that if we were able to devise a method to construct nanomaterials from MOFs while keeping the organic linker unaltered, we would have the opportunity to use it to stabilize the as-formed active sites under CO 2 RR operating conditions.…”

Controlled growth of ultrafine metal nanoparticles mediated by solid supports

“…72 The pore structures of MOFs separates the UMNPs one from another, which can avoid the aggregation of UMNPs during the catalytic process. 73,74 The synthesis and application of MOFs is a current hot research field, and many new MOF structures are reported every year, but not all MOFs are suitable for the synthesis of UMNPs and their application in catalysis. For example, when H 2 O is generated or participates in the catalytic reaction pathway, the framework of MOF-177 can easily decompose and collapse.…”

Can Charge‐Modulated Metal‐Organic Frameworks Achieve High‐Performance CO2 Capture and Separation over H2, N2, and CH4?

“…Carbon capture and storage (CCS) has evolved as a promising strategy, [3–5] in which developing high‐efficiency CO 2 capture and separation materials is the crucial prerequisite [6–8] . Metal‐organic frameworks (MOFs) have attracted extensive interest due to their large surface area, abundant metal sites, and easy functionalization [9–11] . Numerous strategies such as doping, functionalization, and pore topological design have been adopted to improve the CO 2 capture and separation performance [12–14] …”