Precise modulation of electron spin states in metal-organic framework towards exceptional oxygen evolution reaction DOI Creative Commons
Minghua Huang,

Xianbiao Hou,

Tengjia Ni

et al.

Research Square (Research Square), Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 9, 2024

Abstract Spin configuration and coordination environment changes have emerged as promising strategies to boost the oxygen evolution reaction (OER) activity. However, achieving precise gradual regulation of both spin states elucidate structure-activity relationship remains a key priority is rarely reported. In this work, we successfully induce transition Fe sites from low state medium ultimately high by meticulously adjusting within NiFe-MOF, while Ni still keep state. Experimental theoretical calculations confirm polarization electrons migration Fe-t2g Fe-eg orbitals with reduced saturation, which optimizes orbital exchange interactions between ions facilitates adsorption intermediates. The NiFe-MOF-D3 unique NiO6-FeO4 geometric structure exhibits overpotential 328 mV@1 A cm-2 365 [email protected] in alkaline medium. Furthermore, assembled electrolyzer also presents remarkable activity (1.77 V@500 mA cm-2) lower cost ($ 0.94) than target U.S. Department Energy 2.00).

Language: Английский

Regulating Fe Intermediate Spin States via FeN4‐Cl‐Ti Structure for Enhanced Oxygen Reduction DOI
Shuren Zhang, Yitong Han, Rui Zhang

et al.

Advanced Energy Materials, Journal Year: 2024, Volume and Issue: unknown

Published: Sept. 29, 2024

Abstract Modulating the spin states of FeN 4 moieties is critical for enhancing electrocatalytic oxygen reduction reaction (ORR). In this study, Ti N 3 Cl x and O MXenes are synthesized functionalized with iron phthalocyanine (FePc) to form model catalysts well‐defined ‐Cl‐Ti ‐O‐Ti structures, respectively. The structure, formed within /FePc composite, enables precise modulation from low intermediate spin, significantly ORR performance. contrast, structure in shows less effective state modulation, leading comparatively lower activity. Compared FePc /FePc, demonstrates superior electrochemical performance, an half‐wave potential +0.91 V versus RHE doubled power densities Zn–air batteries (214.5 mW cm −2 ). Theoretical studies confirm that induced by weak‐field ligand‐modified facilitate electron filling antibonding orbital composed Fe 3dz 2 π* orbitals, greatly O₂ activation These findings underscore catalytic properties compared ‐O‐Ti, advancing understanding state‐related mechanisms guiding design high‐performance catalysts.

Language: Английский

Citations

1
Reconstructed Hydroxyl Coordination Field Enhances Mass Transfer for Efficient Electrocatalytic Water Oxidation DOI
Haomin Jiang,

Haohai Dong,

Yicheng Liu

et al.

Small, Journal Year: 2024, Volume and Issue: 21(6)

Published: Dec. 29, 2024

Abstract Mass transfer factor plays an indispensable role in high current density to accelerate the oxygen evolution reaction (OER) process, yet research on modulating reactant mass transport remains limited. Herein, by leveraging dual acid‐base properties of aluminum sites, both activation electronic activity layer for layered double hydroxides (LDH) and construction interlayer hydroxide coordination field (IHCF) have been achieved through situ electrochemical reconstruction. It not only facilitates charge surface catalytic transformation intermediates but, most notably, presence IHCF significantly enhances reactants. As a result, overpotential LDHs with is 164 mV, better than reported Ni‐based catalysts. Deuterium kinetic isotope effect experiments pH‐dependence measurements demonstrate that effectively substrate capability structural stability, thereby accelerating proton‐coupled electron process. To further validate characteristics, stability tests alkaline flow electrolyzer show catalysts maintain over 1000 h at density. This work suggests can be utilized design synthesis efficient water oxidation practical application.

Language: Английский

Citations

1
Spontaneous‐Spin‐Polarized 2D π‐d Conjugated Frameworks Towards Enhanced Oxygen Evolution Kinetics DOI Creative Commons
Won Seok Lee, Hiroaki Maeda,

Yen‐Ting Kuo

et al.

Small, Journal Year: 2024, Volume and Issue: unknown

Published: May 28, 2024

Abstract Alternative strategies to design sustainable‐element‐based electrocatalysts enhancing oxygen evolution reaction (OER) kinetics are demanded develop affordable yet high‐performance water‐electrolyzers for green hydrogen production. Here, it is demonstrated that the spontaneous‐spin‐polarized 2D π‐d conjugated framework comprising abundant elements of nickel and iron with a ratio Ni:Fe = 1:4 benzenehexathiol linker (BHT) can improve OER by its unique electronic property. Among bimetallic NiFe x:y ‐BHTs various ratios x:y, ‐BHT exhibits highest activity. The shows specific current density 140 A g −1 at overpotential 350 mV. This performance one best activities among state‐of‐the‐art non‐precious even comparable platinum‐group‐metals RuO 2 IrO . functional theory calculations uncover introducing Ni into homometallic Fe‐BHT (e.g., 0:1) emerge state. Thus, this material achieve improved spin‐polarization which previously required external magnetic fields. work rational frameworks be powerful strategy synthesize promising wide spectrum next‐generation energy devices.

Language: Английский

Citations

0
Visualizing the structure and dynamics of transition metal‐based electrocatalysts using synchrotron X‐ray absorption spectroscopy DOI

Wen Cheng,

Peng Fan, Wei Jin

et al.

ChemSusChem, Journal Year: 2024, Volume and Issue: unknown

Published: Sept. 30, 2024

Abstract As the global energy structure evolves and clean technologies advance, electrocatalysis has become a focal point as critical conversion pathway in new sector. Transitional metal electrocatalysts (TMEs) with their distinctive electronic structures redox properties show great potential electrocatalytic reactions. However, complex reaction mechanisms kinetic limitations hinder improvement of efficiency, highlighting necessity for comprehensive studies on performance electrocatalysts. X‐ray Absorption Fine Structure (XAFS) spectra stand out robust tool examining electrocatalyst′s due to its atomic selectivity sensitivity local environments. This review delves into application XAFS technology characterizing TMEs, providing in‐depth analyses Near‐Edge (XANES) spectra, Extended (EXAFS) both R‐space k ‐space. These reveal intrinsic structural information, interactions, catalyst stability, aggregation morphology. Furthermore, paper examines advancements in‐situ techniques real‐time monitoring active site changes, capturing intermediate transitional states, elucidating evolution species during insights deepen our understanding structure‐activity relationship offer valuable guidance designing developing highly stable

Language: Английский

Citations

0
Precise modulation of electron spin states in metal-organic framework towards exceptional oxygen evolution reaction DOI Creative Commons
Minghua Huang,

Xianbiao Hou,

Tengjia Ni

et al.

Research Square (Research Square), Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 9, 2024

Abstract Spin configuration and coordination environment changes have emerged as promising strategies to boost the oxygen evolution reaction (OER) activity. However, achieving precise gradual regulation of both spin states elucidate structure-activity relationship remains a key priority is rarely reported. In this work, we successfully induce transition Fe sites from low state medium ultimately high by meticulously adjusting within NiFe-MOF, while Ni still keep state. Experimental theoretical calculations confirm polarization electrons migration Fe-t2g Fe-eg orbitals with reduced saturation, which optimizes orbital exchange interactions between ions facilitates adsorption intermediates. The NiFe-MOF-D3 unique NiO6-FeO4 geometric structure exhibits overpotential 328 mV@1 A cm-2 365 [email protected] in alkaline medium. Furthermore, assembled electrolyzer also presents remarkable activity (1.77 V@500 mA cm-2) lower cost ($ 0.94) than target U.S. Department Energy 2.00).

Language: Английский

Citations

0