Unraveling the role of unpaired 3d electrons in e orbital of CoO: Driving π feedback of N2 for efficient ammonia electrosynthesis

Xiong, Yi; Zhao, Liang; Zhao, Rui; Wang, Xiaoxuan; Chi, Xinyue; Zhang, Kaixin; Fu, Zhenzhen; Li, Shuyuan; Wang, Jiaou; Nie, Kaiqi; Yang, Zhiyu; Yan, Yi‐Ming

doi:10.1016/j.cej.2023.144493

Cited by 10 publications

(3 citation statements)

References 64 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This is attributed to the distinct electronic configuration of Co 2+ in CoO, which boasts an unpaired electron arrangement (t 2g 5 e g 2 ) optimizing N 2 adsorption. 14 However, a paradoxical attenuation in the catalytic vigor of Co 2+ emerges during sustained ENRR, a phenomenon that we ascribe to the electron depletion of Co 2+ . Addressing this necessitates astute , paired with a notable FE of 9.6% at a potential of −0.2 V versus RHE.…”

Section: ■ Introductionmentioning

confidence: 75%

“…Notably, among the cobalt oxide variants, CoO trumps Co 2 O 3 in ENRR efficacy. This is attributed to the distinct electronic configuration of Co 2+ in CoO, which boasts an unpaired electron arrangement ( t 2g 5 e g 2 ) optimizing N 2 adsorption . However, a paradoxical attenuation in the catalytic vigor of Co 2+ emerges during sustained ENRR, a phenomenon that we ascribe to the electron depletion of Co 2+ .…”

Section: Introductionmentioning

confidence: 82%

See 1 more Smart Citation

Electronegative Phosphorus-Integrated Co²⁺ Active Sites for Enhanced Electrocatalytic Nitrogen Reduction

Xiong,

Li,

Wang

et al. 2024

Inorg. Chem.

Self Cite

View full text Add to dashboard Cite

In the quest for proficient electrocatalysts for ammonia's electrocatalytic nitrogen reduction, cobalt oxides, endowed with a rich delectron reservoir, have emerged as frontrunners. Despite the previously evidenced prowess of CoO in this realm, its ammonia yield witnesses a pronounced decline as the reaction unfolds, a phenomenon linked to the electron attrition from its Co 2+ active sites during electrocatalytic nitrogen reduction reaction (ENRR). To counteract this vulnerability, we harnessed electron-laden phosphorus (P) elements as dopants, aiming to recalibrate the electronic equilibrium of the pivotal Co active site, thereby bolstering both its catalytic performance and stability. Our empirical endeavors showcased the doped P-CoO's superior credentials: it delivered an impressive ammonia yield of 49.6 and, notably, a Faradaic efficiency (FE) of 9.6% at −0.2 V versus RHE, markedly eclipsing its undoped counterpart. Probing deeper, a suite of ex-situ techniques, complemented by rigorous theoretical evaluations, was deployed. This dual-pronged analysis unequivocally revealed CoO's propensity for an electron-driven valence metamorphosis to Co 3+ post-ENRR. In stark contrast, P-CoO, fortified by P doping, exhibits a discernibly augmented ammonia yield. Crucially, P's intrinsic ability to staunch electron leakage from the active locus during ENRR ensures the preservation of the valence state, culminating in enhanced catalytic dynamism and fortitude. This investigation not only illuminates the intricacies of active site electronic modulation in ENRR but also charts a navigational beacon for further enhancements in this domain.

show abstract

Section: ■ Introductionmentioning

confidence: 75%

Section: Introductionmentioning

confidence: 82%

Electronegative Phosphorus-Integrated Co²⁺ Active Sites for Enhanced Electrocatalytic Nitrogen Reduction

Xiong,

Li,

Wang

et al. 2024

Inorg. Chem.

Self Cite

View full text Add to dashboard Cite

show abstract

“…XANES curves of CoO (T d , a t 2g 5 e g 2 electron configuration) and Co 2 O 3 (O h , a t 2g 6 e g 0 electron configuration) were measured as references. [ 17 ] Firstly, the XANES spectrum at the Co K‐edge of CoCr closely resembles that of Co 2 O 3 with a higher white line (WL) intensity compared to that of as‐Co 3 O 4 . This suggests a higher coordination number (CN) of the Co–O bonds in the CoCr catalyst ( Figure 2 a ).…”

Section: Resultsmentioning

confidence: 98%

Chromium‐Induced High Covalent Co–O Bonds for Efficient Anodic Catalysts in PEM Electrolyzer

Yan,

Feng,

Shi

et al. 2024

Advanced Science

View full text Add to dashboard Cite

The proton exchange membrane water electrolyzer (PEMWE), crucial for green hydrogen production, is challenged by the scarcity and high cost of iridium‐based materials. Cobalt oxides, as ideal electrocatalysts for oxygen evolution reaction (OER), have not been extensively applied in PEMWE, due to extremely high voltage and poor stability at large current density, caused by complicated structural variations of cobalt compounds during the OER process. Thus, the authors sought to introduce chromium into a cobalt spinel (Co3O4) catalyst to regulate the electronic structure of cobalt, exhibiting a higher oxidation state and increased Co–O covalency with a stable structure. In‐depth operando characterizations and theoretical calculations revealed that the activated Co–O covalency and adaptable redox behavior are crucial for facilitating its OER activity. Both turnover frequency and mass activity of Cr‐doped Co3O4 (CoCr) at 1.67 V (vs RHE) increased by over eight times than those of as‐synthesized Co3O4. The obtained CoCr catalyst achieved 1500 mA cm−2 at 2.17 V and exhibited notable durability over extended operation periods – over 100 h at 500 mA cm−2 and 500 h at 100 mA cm−2, demonstrating promising application in the PEMWE industry.

show abstract

From Charge to Spin: An In‐Depth Exploration of Electron Transfer in Energy Electrocatalysis

Sun,

Zhang,

Shi

et al. 2024

Advanced Materials

View full text Add to dashboard Cite

Catalytic materials play crucial roles in various energy‐related processes, ranging from large‐scale chemical production to advancements in renewable energy technologies. Despite a century of dedicated research, major enduring challenges associated with enhancing catalyst efficiency and durability, particularly in green energy‐related electrochemical reactions, remain. Focusing only on either the crystal structure or electronic structure of a catalyst is deemed insufficient to break the linear scaling relationship (LSR), which is the golden rule for the design of advanced catalysts. The discourse in this review intricately outlines the essence of heterogenous catalysis reactions by highlighting the vital roles played by electron properties. The physical and electrochemical properties of electron charge and spin that govern catalysis efficiencies are analyzed. Emphasis is placed on the pronounced influence of external fields in perturbing the LSR, underscoring the vital role that electron spin plays in advancing high‐performance catalyst design. The review culminates by proffering insights into the potential applications of spin catalysis, concluding with a discussion of extant challenges and inherent limitations. This article is protected by copyright. All rights reserved

show abstract

Unraveling the role of unpaired 3d electrons in e orbital of CoO: Driving π feedback of N2 for efficient ammonia electrosynthesis

Cited by 10 publications

References 64 publications

Electronegative Phosphorus-Integrated Co²⁺ Active Sites for Enhanced Electrocatalytic Nitrogen Reduction

Electronegative Phosphorus-Integrated Co²⁺ Active Sites for Enhanced Electrocatalytic Nitrogen Reduction

Chromium‐Induced High Covalent Co–O Bonds for Efficient Anodic Catalysts in PEM Electrolyzer

From Charge to Spin: An In‐Depth Exploration of Electron Transfer in Energy Electrocatalysis

Contact Info

Product

Resources

About

Unraveling the role of unpaired 3d electrons in e orbital of CoO: Driving π feedback of N2 for efficient ammonia electrosynthesis

Cited by 10 publications

References 64 publications

Electronegative Phosphorus-Integrated Co2+ Active Sites for Enhanced Electrocatalytic Nitrogen Reduction

Electronegative Phosphorus-Integrated Co2+ Active Sites for Enhanced Electrocatalytic Nitrogen Reduction

Chromium‐Induced High Covalent Co–O Bonds for Efficient Anodic Catalysts in PEM Electrolyzer

From Charge to Spin: An In‐Depth Exploration of Electron Transfer in Energy Electrocatalysis

Contact Info

Product

Resources

About

Electronegative Phosphorus-Integrated Co²⁺ Active Sites for Enhanced Electrocatalytic Nitrogen Reduction

Electronegative Phosphorus-Integrated Co²⁺ Active Sites for Enhanced Electrocatalytic Nitrogen Reduction