Combined Experimental and Theoretical Study of Cobalt Corroles as Catalysts for Oxygen Reduction Reaction

Shpilman, Jennifer S.; Friedman, Ariel; Zion, Noam; Levy, Naomi; Major, Dan Thomas; Elbaz, Lior

doi:10.1021/acs.jpcc.9b09203

Cited by 29 publications

(21 citation statements)

References 52 publications

(81 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Next, the number ( n ) of electrons transferred per O 2 molecule with 1 /CNT was determined to be 3.97 based on RRDE results, while it was 3.84 with 2 /CNT (Figure 3 b). Similar n values were obtained by using Koutecky–Levich (K–L) analyses (Figures S24, S25) [60, 61] . The durability of 1 /CNT was then evaluated, showing almost no loss of electrocatalytic ORR activity after 1000 CV cycles (Figure 3 c).…”

Section: Figuresupporting

confidence: 71%

See 1 more Smart Citation

Enzyme‐Inspired Iron Porphyrins for Improved Electrocatalytic Oxygen Reduction and Evolution Reactions

et al. 2021

View full text Add to dashboard Cite

Nature uses Fe porphyrin sites for the oxygen reduction reaction (ORR). Synthetic Fe porphyrins have been extensively studied as ORR catalysts, but activity improvement is required. On the other hand, Fe porphyrins have been rarely shown to be efficient for the oxygen evolution reaction (OER). We herein report an enzyme‐inspired Fe porphyrin 1 as an efficient catalyst for both ORR and OER. Complex 1, which bears a tethered imidazole for Fe binding, beats imidazole‐free analogue 2, with an anodic shift of ORR half‐wave potential by 160 mV and a decrease of OER overpotential by 150 mV to get the benchmark current density at 10 mA cm−2. Theoretical studies suggested that hydroxide attack to a formal FeV=O form the O−O bond. The axial imidazole can prevent the formation of trans HO‐FeV=O, which is less effective to form O−O bond with hydroxide. As a practical demonstration, we assembled rechargeable Zn‐air battery with 1, which shows equal performance to that with Pt/Ir‐based materials.

show abstract

Section: Figuresupporting

confidence: 71%

“…Similar n values were obtained by using Koutecky-Levich (K-L) analyses ( Figures S24, S25). [60,61] The durability of 1/ CNT was then evaluated, showing almost no loss of electrocatalytic ORR activity after 1000 CV cycles (Figure 3 c). In prolonged electrolysis, the catalytic ORR current with 1/CNT dropped only by < 6 % after 10 h ( Figure S26).…”

Section: Chemiementioning

confidence: 99%

Enzyme‐Inspired Iron Porphyrins for Improved Electrocatalytic Oxygen Reduction and Evolution Reactions

et al. 2021

View full text Add to dashboard Cite

show abstract

“…In the past few years, we have investigated the catalytic activity of metallo‐corroles towards ORR in acidic and alkaline media [14–21] . In these studies, different metal centers and substituents were introduced to the corroles ring.…”

Section: Introductionmentioning

confidence: 99%

Control of Molecular Catalysts for Oxygen Reduction by Variation of pH and Functional Groups

et al. 2021

Self Cite

View full text Add to dashboard Cite

In the search for replacement of the platinum‐based catalysts for fuel cells, MN4 molecular catalysts based on abundant transition metals play a crucial role in modeling and investigation of the influence of the environment near the active site in platinum‐group metal‐free (PGM‐free) oxygen reduction reaction (ORR) catalysts. To understand how the ORR activity of molecular catalysts can be controlled by the active site structure through modification by the pH and substituent functional groups, the change of the ORR onset potential and the electron number in a broad pH range was examined for three different metallocorroles. Experiments revealed a switch between two different ORR mechanisms and a change from 2e− to 4e− pathway in the pH range of 3.5‐6. This phenomenon was shown by density functional theory (DFT) calculations to be related to the protonation of the nitrogen atoms and carboxylic acid groups on the corroles indicated by the pKa values of the protonation sites in the vicinity of the ORR active sites. Control of the electron‐withdrawing nature of these groups characterized by the pKa values could switch the ORR from the H+ to e− rate‐determining step mechanisms and from 2e− to 4e− ORR pathways and also controlled the durability of the corrole catalysts. The results suggest that protonation of the nitrogen atoms plays a vital role in both the ORR activity and durability for these materials and that pKa of the N atoms at the active sites can be used as a descriptor for the design of high‐performance, durable PGM‐free catalysts.

show abstract

“…Studies have shown that the stability of high‐valent metal–oxo intermediates greatly affects the catalytic performance of ORR. [ 95–97 ] The corrole ring exhibits three protons instead of two, which allows corrole to stabilize high‐oxidation‐state transition metals. Recent studies on metal corroles have found that when the central metal ion was Co(III), the catalyst exhibited the highest ORR activity.…”

Section: Carbon Nanotube/mmc Orr Catalystsmentioning

confidence: 99%

“…The various substituents on the macrocyclic ligand and the electron‐donating, electron‐withdrawing, and π‐conjugated characteristics of the fifth axial ligand can adjust the electron‐cloud density of the central metal ion, thereby indirectly affecting the interaction between the central metal ion and the reaction intermediates. [ 69,77,81,94–97,124,128 ] Owing to the difference in ring size, the best porphyrin and phthalocyanine ORR performance was obtained when the central metal ion was cobalt and iron, respectively. The phthalocyanine ligand can provide more electrons to the central Fe ion than porphyrin can, which weakens the iron's oxygen adsorption.…”

Section: Guidelines For Developing Mmc‐functionalized Carbon‐based Orr Electrocatalystsmentioning

confidence: 99%

Molecular Control of Carbon‐Based Oxygen Reduction Electrocatalysts through Metal Macrocyclic Complexes Functionalization

Hong

Huang

et al. 2021

Advanced Energy Materials

View full text Add to dashboard Cite

Owing to their zero pollution and high efficiency, fuel cells and metal–air batteries show great potential for broad application to sustainable energy technologies. However, the use of expensive and scarce Pt‐based materials as cathode catalysts to overcome the slow kinetics of oxygen‐reduction reaction (ORR) limits the scalability of such devices. Recently, considerable progress has been made in the development of nonprecious‐metal ORR catalysts. Although metal macrocyclic complexes (MMC) exhibiting a well‐defined M‐N4 (M = Fe, Co, Mn, Cu, etc.) structure (which can provide open sites to combine with oxygen and catalyze ORR) have attracted widespread attention, the MMC ORR performance is usually unsatisfactory because MCCs exhibit poor conductivity, symmetric electron distribution, inferior O2 adsorption, and low activation. However, MMC‐modified conductive‐carbon materials effectively solve such problems and simultaneously boost the ORR catalytic activity. In this review, the recent achievements in MMC‐functionalized carbon materials as ORR catalysts are summarized, and the current challenges and prospects of MMC‐functionalized carbon‐based ORR catalysts are discussed based on recent experimental and theoretical studies.

show abstract

Combined Experimental and Theoretical Study of Cobalt Corroles as Catalysts for Oxygen Reduction Reaction

Cited by 29 publications

References 52 publications

Enzyme‐Inspired Iron Porphyrins for Improved Electrocatalytic Oxygen Reduction and Evolution Reactions

Enzyme‐Inspired Iron Porphyrins for Improved Electrocatalytic Oxygen Reduction and Evolution Reactions

Control of Molecular Catalysts for Oxygen Reduction by Variation of pH and Functional Groups

Molecular Control of Carbon‐Based Oxygen Reduction Electrocatalysts through Metal Macrocyclic Complexes Functionalization

Contact Info

Product

Resources

About