Synergistic electroreduction of carbon dioxide to carbon monoxide on bimetallic layered conjugated metal-organic frameworks

Abstract

Highly effective electrocatalysts promoting CO 2 reduction reaction (CO 2 RR) is extremely desirable to produce value-added chemicals/fuels while addressing current environmental challenges. Herein, we develop a layer-stacked, bimetallic two-dimensional conjugated metalorganic framework (2D c-MOF) with copper-phthalocyanine as ligand (CuN 4) and zinc-bis (dihydroxy) complex (ZnO 4) as linkage (PcCu-O 8-Zn). The PcCu-O 8-Zn exhibits high CO selectivity of 88%, turnover frequency of 0.39 s −1 and long-term durability (>10 h), surpassing thus by far reported MOF-based electrocatalysts. The molar H 2 /CO ratio (1:7 to 4:1) can be tuned by varying metal centers and applied potential, making 2D c-MOFs highly relevant for syngas industry applications. The contrast experiments combined with operando spectroelectrochemistry and theoretical calculation unveil a synergistic catalytic mechanism; ZnO 4 complexes act as CO 2 RR catalytic sites while CuN 4 centers promote the protonation of adsorbed CO 2 during CO 2 RR. This work offers a strategy on developing bimetallic MOF electrocatalysts for synergistically catalyzing CO 2 RR toward syngas synthesis.

Gas Diffusion Strategy for Inserting Atomic Iron Sites into Graphitized Carbon Supports for Unusually High‐Efficient CO2 Electroreduction and High‐Performance Zn–CO2 Batteries

“…[8] However, it is still a big challenge to synthesize robust SACs with stable, but reactive, metal sites at the atomic scale due to their high surface energies. To achieve atomic dispersion of metal species on carbon-based substrates or metal compounds, various traditional chemical routes, such as: 1) solvent strategy that using solvent dispersion effect, [9][10][11][12][13] 2) carrier modification strategy that designing load sites for anchoring metal atoms, [14] 3) metal-organic molecular strategy that synthesizing metal-organic framework based on isolated metal nodes, [15,16] and 4) additional energy strategy that utilizing external energy for doping of metals as isolated atoms, [17][18][19][20][21][22] have been explored. Among them, the solvent-based procedures, including impregnation/ion-exchange, [9] iced-photochemistry, [10] precursor-dilution strategy, [11] lyophilization, [12] and electrospinning, [13] are universal for producing homogeneous dispersions of different atomic metal species, although they are normally associated with a high waste cost and low yield.…”

“…Among them, the solvent-based procedures, including impregnation/ion-exchange, [9] iced-photochemistry, [10] precursor-dilution strategy, [11] lyophilization, [12] and electrospinning, [13] are universal for producing homogeneous dispersions of different atomic metal species, although they are normally associated with a high waste cost and low yield. In contrast, both carrier modification strategy and metalorganic molecular strategy often suffer from tedious substrate modification (e.g., defect engineering) [14] or complicated complex organic synthesis (e.g., porphyrinic triazine-derived frameworks [15] and conjugated metal-organic frameworks [16] ). Moreover, additional energy strategies, including atomic layer deposition, [17] galvanic replacement, [18] microwave, [19] high temperature migration, [20] high temperature shockwave, [21] and metal bulk transformation, [22] are often energy intensive, involving expensive equipment and/or extreme conditions (e.g., high temperature input).…”

POM‐Incorporated CoO Nanowires for Enhanced Photocatalytic Syngas Production from CO2

“…It is notable that the product of CoO-Mo8 UNWs delivers a higher ratio of CO/H 2 , which would be a more beneficial ratio for the subsequent thermochemical conversions including Fischer-Tropsch process and methanation. [42] As comparison, H 2 /CO production rates are only 4422/1202 mmol g À1 h À1 for CoO NWBs and 6154/2384 mmol g À1 h À1 for CoO-Mo8 NWBs. Interestingly, CoO-Mo8 NWBs not only present higher photocatalytic activity, but also deliver a higher CO/ H 2 ratio, indicating that the incorporation of Mo8 could tune the selectivity towards CO 2 reduction.…”

d-Orbital steered active sites through ligand editing on heterometal imidazole frameworks for rechargeable zinc-air battery

“…In response, molecules with conjugated heteroaromatic organic components, such as covalent organic frameworks (COFs), hydrogen-bonded organic frameworks (HOFs) and metal-organic frameworks (MOFs), provide a possible solution to effectively resist against the attack from the oxygen free radicals 27 – 29 . As a subfamily of MOFs, zeolite imidazole frameworks (ZIFs) with excellent water and alkaline tolerance endow great promise in ZABs application 30 , 31 .…”