Nitrogen‐Doped Hierarchical Porous Carbon Architecture Incorporated with Cobalt Nanoparticles and Carbon Nanotubes as Efficient Electrocatalyst for Oxygen Reduction Reaction

Chen, Zhu; Kim, Cheong; Aoki, Yoshitaka; Habazaki, H.

doi:10.1002/admi.201700583

Cited by 23 publications

(6 citation statements)

References 75 publications

(90 reference statements)

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“…It is noted that the pyrolysis of the nitrate-starch gel is a well-known solution combustion synthesis (SCS) process, which generates an exothermic and self-sustaining redox reaction with the emission of a large amount of gases in a short time. The SCS reaction condition was evaluated according to the calculation of equivalence ratio, ϕ, which is the ratio of the total valencies of fuels to nitrate oxidizers. − Here, a ϕ value larger than 1 represents a fuel-rich condition in a conventional SCS process in air/oxygen atmosphere. The ϕ values were calculated to be 1.20, 1.44, 1.92, and 2.40 for starch amount of st05, st06, st08, and st10, respectively.…”

Section: Results and Discussionmentioning

confidence: 99%

Starch-Derived Hierarchical Porous Carbon with Controlled Porosity for High Performance Supercapacitors

Jian

Chen

Aoki

et al. 2018

ACS Sustainable Chem. Eng.

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124

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The development of green and clean synthetic techniques to produce carbon materials for energy storage and conversion applications has motivated researchers to use sustainable biomass. In this study, hierarchical porous carbon (HPC) with very high specific surface area and controlled porosity is synthesized by a novel and facile method, which employs an exothermic pyrolysis process of starch−magnesium nitrate raw materials with subsequent high temperature thermal treatment and acid washing. The biomass starch acts as both a reductant and carbon source, while magnesium nitrate is an oxidant and provides MgO template as pore creator. The vigorous exothermic pyrolysis of starch−magnesium nitrate mixture introduces MgO@C precursor with a highly 3D porous network containing meso-and macropores. After MgO template is removed, plenty of micro-and mesopores are further created. Experimental parameters including calcination temperature, starch−nitrate ratio, and magnesium salt species are comprehensively evaluated. The HPC shows a very large specific surface area up to about 2300 m 2 g −1 and a hierarchical porous architecture composed of interconnected micro-, meso-and macropores. As an electrode material for supercapacitors, the HPC exhibits high specific capacitance (229 F g −1 at 1 A g −1 in a 6 M KOH electrolyte), good rate capability (211 F g −1 at even 10 A g −1 ) and outstanding cycling stability (94% capacitance retention after 10 000 cycles at 2 A g −1 ). The superior electrochemical performance of the HPC stems from both high surface area and the hierarchical multiporous structure, which provides an accessible pathway for electrolyte transport. These results demonstrate a very effective and low-cost method for scalable preparation of HPC using green biomass carbon source for supercapacitors, which also has potential applications such as adsorbent for water/gas treatment.

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Section: Results and Discussionmentioning

confidence: 99%

Starch-Derived Hierarchical Porous Carbon with Controlled Porosity for High Performance Supercapacitors

Jian

Chen

Aoki

et al. 2018

ACS Sustainable Chem. Eng.

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124

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“…The electrocatalytic performance of the decorated graphene should arise from the high specific surface area. However, many studies reported that the metal aggregation during high‐temperature pyrolysis processes probably decreases electrocatalytic activity . Therefore, graphene with highly‐dispersed CoN x species could be an ideal electrocatalyst if metal nanoparticles are prevented from aggregating during carbonization …”

Section: Methodsmentioning

confidence: 99%

Rational Design of Single Atomic Co in CoN_x Moieties on Graphene Matrix as an Ultra‐Highly Efficient Active Site for Oxygen Reduction Reaction

et al. 2020

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The sharp increase in current energy consumption needs the development of fuel cells (FCs) as one of sustainable, renewable, efficient and eco-friendly electrochemical conversion systems of energy. The performance of electrocatalysts is crucially important for commercialization of FCs. Commercial Pt based catalysts are used due to their high catalytic activity. However, widespread commercialization is impossible because of the scarcity and poor durability of Pt based catalysts. We are on our quest to find a more stable and affordable alternative catalyst of Pt based catalysts. In particular, single-atom catalysts supported on graphene are greatly attractive because of their unique characteristic and high catalytic activity. In this work, graphene is hydrothermally treated by sulfuric acid to introduce the ion-exchanging sites. Then, Co 2 + ion-exchanging, 2-methylimidazole coordination and pyrolysis process are subsequently conducted to prepare highly-dispersed single-atom Co species catalyst with outstanding ORR activity and durability. This work presents a new direction for a rational design of single-atom catalyst on carbon matrix.

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“…42 Furthermore, glycine (NH 2 −CH 2 −COOH) was used both as the carbon and nitrogen source to stabilize the transition metals by interacting with the −NH 2 group in glycine, which may reduce the reaction energy barrier at the rate-determining step (RDS). 43 We argued that with the synergistic advantages of an adjustable hierarchical porous structure, a high electrochemical active surface area (ECSA), and Ni−N interactions, the as-prepared Ni@MicroPNC should exhibit enhanced ECO2RR performances.…”

Section: Introductionmentioning

confidence: 99%

Synergistic Interaction between the Ni-Center and Glycine-Derived N-Doped Porous Carbon Material Boosts Electrochemical CO₂ Reduction

Zhu,

Mulder,

Rokicińska

et al. 2024

ACS Catal.

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Electrochemical conversion of CO 2 into CO is highly attractive since CO is highly valuable for its wide use in organic synthesis as well as a fuel-type molecule. However, the selective formation of CO from CO 2 is highly sensitive to the variation of particle size, coordination number, and defects in the electrocatalyst. Considering this, we report a boosted electrochemical CO 2 reduction performance on a Ni, N-codoped hierarchical porous carbon material (Ni@MicroPNC) by exposing substantial active sites during the carbonization process by using ZnCl 2 as the porous template agent due to its relatively low boiling point. A particular advantage of our electrocatalyst is that the support (N-doped hierarchical porous carbon material) of the Ni-catalyst is synthesized by using glycine as a carbon precursor. To our observation, the as-prepared Ni@MicroPNC catalyst displayed a high CO faradaic efficiency (FE) of 92.8% with a high partial current density (j co ) of 22.4 mA cm −2 and outstanding current density stability at −0.81 V (vs RHE) for 10 h. The suggested high CO selectivity and catalytic stability of Ni@MicroPNC are attributed to the synergistic effect of high specific surface area, optimized hierarchical structure, Ni, N codoping into the porous carbon material, and relatively weaker CO binding strength. Furthermore, DFT calculations indicate that the doped N atom interacted with the Ni center to lower the energy barrier of *CO desorption. This finding provides a facile strategy for the synthesis of low-cost and highly active nanoparticle-based electrocatalysts for a selective reduction of CO 2 into CO.

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Nitrogen‐Doped Hierarchical Porous Carbon Architecture Incorporated with Cobalt Nanoparticles and Carbon Nanotubes as Efficient Electrocatalyst for Oxygen Reduction Reaction

Cited by 23 publications

References 75 publications

Starch-Derived Hierarchical Porous Carbon with Controlled Porosity for High Performance Supercapacitors

Starch-Derived Hierarchical Porous Carbon with Controlled Porosity for High Performance Supercapacitors

Rational Design of Single Atomic Co in CoN_x Moieties on Graphene Matrix as an Ultra‐Highly Efficient Active Site for Oxygen Reduction Reaction

Synergistic Interaction between the Ni-Center and Glycine-Derived N-Doped Porous Carbon Material Boosts Electrochemical CO₂ Reduction

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Nitrogen‐Doped Hierarchical Porous Carbon Architecture Incorporated with Cobalt Nanoparticles and Carbon Nanotubes as Efficient Electrocatalyst for Oxygen Reduction Reaction

Cited by 23 publications

References 75 publications

Starch-Derived Hierarchical Porous Carbon with Controlled Porosity for High Performance Supercapacitors

Starch-Derived Hierarchical Porous Carbon with Controlled Porosity for High Performance Supercapacitors

Rational Design of Single Atomic Co in CoNx Moieties on Graphene Matrix as an Ultra‐Highly Efficient Active Site for Oxygen Reduction Reaction

Synergistic Interaction between the Ni-Center and Glycine-Derived N-Doped Porous Carbon Material Boosts Electrochemical CO2 Reduction

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Product

Resources

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Rational Design of Single Atomic Co in CoN_x Moieties on Graphene Matrix as an Ultra‐Highly Efficient Active Site for Oxygen Reduction Reaction

Synergistic Interaction between the Ni-Center and Glycine-Derived N-Doped Porous Carbon Material Boosts Electrochemical CO₂ Reduction