Immobilization strategies for porphyrin-based molecular catalysts for the electroreduction of CO₂

Abstract

The ever-growing levels of carbon dioxide (CO2) in our atmosphere, is at once a threat and an opportunity. The development of sustainable and cost-effective pathways to convert CO2 to value-added...

CO2 Electrolysis via Surface-Engineering Electrografted Pyridines on Silver Catalysts

“…Three classes frequently used and modified are bulk transition metals, nanoparticles, − and molecular catalysts. , Both seek to activate the linear CO 2 molecule toward the desired product at enhanced reaction rates while simultaneously limiting the electrochemical activity of the competing HER. The commonly utilized transition-metal catalysts are silver and copper, with common catalytic modifications to enhance the performance occurring as a result of varying morphologies and surface areas. − Alternatively, molecular catalysts range broadly from single-metal sites such as porphyrin and phthalocyanines − to metal-free catalysts (e.g., pyridine), − with modifications accessible by varying chain lengths, metal sites, and supporting ring structures. For these systems, the interactions between aqueous CO 2 and the molecular catalyst’s ligands can act as a capturing site for CO 2 , while the designed center sites can provide the conversion step.…”

Tandem electrocatalytic CO2 reduction with Fe-porphyrins and Cu nanocubes enhances ethylene production

“…Specically, Fe-TBTPP exhibits the highest TOF CO (0.26 s The carbon nanotubes were chosen as commonly used as a conductive support to homogeneously disperse the molecular catalysts via noncovalent interactions. [32][33][34] The reported FE and TOF values are the average of three independent experiments with error bars indicating the standard deviations. −0.55 V vs. RHE), the addition of the Fe-Por to Cu cub suppresses the hydrogen evolution reaction (HER) and enhances the production of CO and formate.…”

“…Iron porphyrin (F-Por) molecular catalysts are selected as the COproducing entity because of their high efficiency for CO 2 to CO conversion at neutral pH when immobilized on conductive substrates. [32][33][34] Furthermore, their versatile chemistry enables facile tuning of their redox behaviors via modication of the psystem. [35][36][37] To this end, we synthesized three Fe-Por with different numbers of orbitals involved in the p-system.…”

“…These measurements were performed at Fe-Por loadings of 16 nmol cm −2 on carbon nanotubes deposited onto glassy carbon electrodes (S = 1.33 cm 2 ) using an H-cell with CO 2 saturated 0.1 M KHCO 3 electrolyte. The carbon nanotubes were chosen as commonly used as a conductive support to homogeneously disperse the molecular catalysts via noncovalent interactions [32][33][34]. The reported FE and TOF values are the average of three independent experiments with error bars indicating the standard deviations.…”

Advancing integrated CO2 electrochemical conversion with amine-based CO2 capture: a review

“…[5][6][7] However, the state-of-the-art CO 2 electrolysis usually uses pure CO 2 as the feed, while CO 2 is diluted in most industrial sources (<20% for flue gases from blast furnaces and post-combustion power plants [8][9][10] ). 5,[11][12][13][14][15][16][17][18][19][20][21] When implemented in practice, CO 2 electrolysis requires costly upstream CO 2 capture processes 22,23 to concentrate CO 2 , and an energy-intensive product separation process 24,25 to recycle CO 2 and concentrate product streams. In addition, gaseous CO 2 reacts with hydroxide ions generated within CO 2 electroreduction systems to form (bi)carbonate.…”