Bifunctional CoNx embedded graphene electrocatalysts for OER and ORR: A theoretical evaluation

Zhang, Xilin; Yang, Zongxian; Lu, Zhansheng; Wang, Weichao

doi:10.1016/j.carbon.2017.12.121

Cited by 230 publications

(123 citation statements)

References 53 publications

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“…The adsorption free energy is defined as ΔG ads = ΔE ads + ΔZPE − TΔS, where ΔE ads , ΔZPE, T, and ΔS are the binding energy, energy difference of zero-point energy, temperature (here, 298.15 K was considered), and change in entropy, respectively. In fact, the ZPE and the entropy of the adsorbed ORR species on different catalysts have similar values, as summarized in previous works 53 so that ΔG *OOH = ΔE *OOH + 0.40, ΔG *O = ΔE *O + 0.05, and ΔG *OH = ΔE *OH + 0.35. 54 According to the above methods, the reaction free energy change of each step can be calculated.…”

Section: Gibbs Free Energysupporting

confidence: 78%

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Exploring the catalytic activity of metal‐fullerene C ₅₈ M (M = Mn, Fe, Co, Ni, and Cu) toward oxygen reduction and CO oxidation by density functional theory

Chen

Chang

et al. 2019

Int J Energy Res

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Summary In the present work, the catalytic activity of metal‐fullerene C58M (M = Mn, Fe, Co, Ni, and Cu) toward oxygen reduction reaction (ORR) and CO oxidation has been explored by detailed density functional theory calculations. Firstly, the binding energy of various ORR species (OOH, O, and OH) on C58M and the corresponding adsorption structures are calculated. The results show that the adsorption strength of any ORR species on C58M follows the order of C58Mn > C58Fe > C58Co > C58Ni > C58Cu and C58Co shows the closest binding energy compared with the Pt(111) surface. Further analysis of the free energy change of ORR indicates that C58Co, C58Ni, and C58Fe have different degrees of catalytic activities, with the calculated free energy change of rate‐determining step of −0.70, −0.32, and −0.04 eV, respectively. On the basis of the above results, the C58Co obviously has the highest ORR activity, with a relatively small overpotential of 0.53 V. In addition, the adsorption free energy of OH can be used as a good descriptor for ORR activity due to the nearly linear relationships between ∆G*OOH, ∆G*O, and ∆G*OH. At last, the catalytic property of C58Co toward CO oxidation reaction is also explored. The calculated results show that CO oxidation on C58Co follows LH mechanism and the rate‐determining step is recognized as *CO + *O2 → *OOCO, with the energy change of −0.13 eV.

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Section: Gibbs Free Energysupporting

confidence: 78%

“…It is well known that Gibbs free energy is an efficient indicator to investigate the ORR catalytic ability . The Gibbs free energy of each ORR step can be calculated by the following equations:

∆ G_{1} = ∆ G_{* OOH} - 4.92,

∆ G_{2} = ∆ G_{* normalO} - ∆ G_{* OOH},

∆ G_{3} = ∆ G_{* OH} - ∆ G_{* normalO},

∆ G_{4} = - ∆ G_{* OH},

…”

Section: Resultsmentioning

confidence: 99%

Exploring the catalytic activity of metal‐fullerene C ₅₈ M (M = Mn, Fe, Co, Ni, and Cu) toward oxygen reduction and CO oxidation by density functional theory

Chen

Chang

et al. 2019

Int J Energy Res

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“…For the purpose of gaining an in‐depth insight into the structure–reactivity relationship between different types of Co‐N 4− x C x ( x =0–4) active sites and ORR performance, DFT calculations were performed (more computational details are in the Supporting Information). We have constructed different types of computational models for CoN 4− x C x active sites, that is, CoN 4 , CoN 3 C 1 , CoN 2 C 2 with different positions of N and C, CoN 1 C 3 , and CoC 4 …”

Section: Resultsmentioning

confidence: 99%

Understanding the Activity of Co‐N_4−xC_x in Atomic Metal Catalysts for Oxygen Reduction Catalysis

et al. 2020

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Atomic metal catalysis (AMC) provides an effective way to enhance activity for the oxygen reduction reaction (ORR). Cobalt anchored on nitrogen‐doped carbon materials have been extensively reported. The carbon‐hosted Co‐N4 structure was widely considered as the active site; however, it is very rare to investigate the activity of Co partially coordinated with N, for example, Co‐N4−xCx. Herein, the activity of Co‐N4−xCx with tunable coordination environment is investigated as the active sites for ORR catalysis. The defect (di‐vacancies) on carbon is essential for the formation of Co‐N4−xCx. N species play two important roles in promoting the intrinsic activity of atomic metal catalyst: N coordinated with Co to manipulate the reactivity by modification of electronic distribution and N helped to trap more Co to increase the number of active sites.

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“…The polypyrrole can also be replaced with the polyethyleneimine as the N source . The ORR performance of these Co−N−C materials is mainly ascribed to the CoN 4 species, which also have been evaluated based on the DFT calculation . To further improve the ORR performance, the other non‐metal atoms such as B, P, and S also have been introduced to the M−N−C system .…”

Section: D Metal‐nitrogen‐carbon Materials For the Oxygen Reduction mentioning

confidence: 99%

“…[126] The ORR performance of these CoÀ NÀ C materials is mainly ascribed to the CoN 4 species, which also have been evaluated based on the DFT calculation. [127] To further improve the ORR performance, the other non-metal atoms such as B, P, and S also have been introduced to the MÀ NÀ C system. [128][129][130][131] The introduce of B atom can accelerate the adsorption of O 2 molecule around the CoÀ N x sites.…”

Section: D Metal-nitrogen-carbon Materials For the Oxygen Reduction mentioning

confidence: 99%

Importance of Electrocatalyst Morphology for the Oxygen Reduction Reaction

2019

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Proton/anion‐exchange membrane fuel cells (PEMFC and AEMFC), generating electricity from the H2 energy with zero‐carbon emission, have become very promising energy conversion devices to meet the increasing energy demand and reduce the dependence on fossil fuels. Currently, platinum (Pt) based materials have proven to be the most efficient electrocatalysts for the oxygen reduction reaction (ORR) at the cathode of the PEMFC and AEMFC. However, the high price and the limited reserve of Pt greatly hinder their industrial applications. Recently, transition metal‐nitrogen‐carbon (M−N−C) based material, as an efficient alternative to replace the precious metal Pt‐based material, has attracted researchers’ attention. Great contributions have been devoted to develop M−N−C based electrocatalysts. This review summarizes recent advances on M−N−C based electrocatalysts used for ORR from the point view of morphology. One‐dimensional (1D), two‐dimensional (2D), three‐dimensional (3D) and multi‐dimensional (MD) M−N−C materials were discussed thoroughly with particular attention on the relationship between the structure and the catalytic activity.

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Bifunctional CoNx embedded graphene electrocatalysts for OER and ORR: A theoretical evaluation

Cited by 230 publications

References 53 publications

Exploring the catalytic activity of metal‐fullerene C ₅₈ M (M = Mn, Fe, Co, Ni, and Cu) toward oxygen reduction and CO oxidation by density functional theory

Exploring the catalytic activity of metal‐fullerene C ₅₈ M (M = Mn, Fe, Co, Ni, and Cu) toward oxygen reduction and CO oxidation by density functional theory

Understanding the Activity of Co‐N_4−xC_x in Atomic Metal Catalysts for Oxygen Reduction Catalysis

Importance of Electrocatalyst Morphology for the Oxygen Reduction Reaction

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Bifunctional CoNx embedded graphene electrocatalysts for OER and ORR: A theoretical evaluation

Cited by 230 publications

References 53 publications

Exploring the catalytic activity of metal‐fullerene C 58 M (M = Mn, Fe, Co, Ni, and Cu) toward oxygen reduction and CO oxidation by density functional theory

Exploring the catalytic activity of metal‐fullerene C 58 M (M = Mn, Fe, Co, Ni, and Cu) toward oxygen reduction and CO oxidation by density functional theory

Understanding the Activity of Co‐N4−xCx in Atomic Metal Catalysts for Oxygen Reduction Catalysis

Importance of Electrocatalyst Morphology for the Oxygen Reduction Reaction

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Exploring the catalytic activity of metal‐fullerene C ₅₈ M (M = Mn, Fe, Co, Ni, and Cu) toward oxygen reduction and CO oxidation by density functional theory

Exploring the catalytic activity of metal‐fullerene C ₅₈ M (M = Mn, Fe, Co, Ni, and Cu) toward oxygen reduction and CO oxidation by density functional theory

Understanding the Activity of Co‐N_4−xC_x in Atomic Metal Catalysts for Oxygen Reduction Catalysis