Honeycomb-like carbon for electrochemical energy storage and conversion

Fan, Huailin; Zhou, Shuxin; Wei, Qinghong; Hu, Xun

doi:10.1016/j.rser.2022.112585

Cited by 23 publications

(4 citation statements)

References 175 publications

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“…Particularly, a large number of oxygen-containing functional groups in CTP undergo crosslinking reaction at high temperature to form uniform carbonoxygen defects (e.g., COC, CO) with high reactivity (Table S1, Supporting Information). [51,53] When the defective carbon support is immersed in H 2 PtCl 6 solution, a typical "galvanic cell effect" will be formed due to the potential difference between oxygen-containing functional groups at defects and PtCl 6 2− ions. [54] A spontaneous redox reaction happens, i.e., the reduction of Pt 4+ and the oxidation of oxygen-containing functional groups.…”

Section: Synthesis and Structural Characterizationmentioning

confidence: 99%

Novel (Pt‐O_x)‐(Co‐O_y) Nonbonding Active Structures on Defective Carbon from Oxygen‐Rich Coal Tar Pitch for Efficient HER and ORR

et al. 2022

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cells as important energy storage and conversion devices will increase rapidly. It is crucial to develop excellent electrocatalysts for hydrogen evolution reaction (HER) and oxygen reduction reaction (ORR) in order to decrease energy consumption. [1,2] Pt is the most effective catalyst for HER and ORR. However, the loading mass of Pt is still high for commercial Pt/C catalysts. Therefore, high cost and limited natural abundance greatly limit wide application of Pt catalyst. [3][4][5] Although nonprecious metal catalysts have been widely studied, it is difficult to replace Pt due to low catalytic activity. [6,7] Effective atomic utilization of Pt is a feasible route to obviously decrease the loading mass and ensure high activity simultaneously.Recently, single-atom catalysts with the highest mass activity and maximum Pt utilization efficiency are developed. [8,9] However, the activities are still low due to unfavorable adsorption/desorption properties of intermediates. [10,11] In fact, besides the intrinsic property of Pt, strong electronic interactions between metal and support and local coordination structure of Pt atoms are crucial to the catalytic activity based on the adjustment of electron distribution. [12][13][14] By modulating the surface chemical field of the support, Pt atoms can be sterically confined to the support and local chemical properties can be effectively adjusted to prevent possible deactivation induced by aggregation. [15,16] Meanwhile, strong coupling of Pt species to the support facilitates electron transfer and ultimately enhances the catalytic activity. [17] Various strategies, such as defect engineering, spatial confinement, and local atomic coordination, are developed to anchor Pt single atoms (Pt-SAs) on modifying carbon supports. [18][19][20] Particularly, great attempts have been devoted to constructing active coordination structures, such as Pt-N x and Pt-C x . [21][22][23] In addition, a preliminary phenomenon is found that the catalytic activity of Pt supported on oxidized carbon supports is significantly better than that on unoxidized carbon supports. [24,25] In fact, it is known that Pt exhibits special affinity to O in many oxygen-containing metal supports, such as polyoxometalates and metal oxides (CuO, TiO 2 , Fe 2 O 3 , CeO 2 ), [26][27][28][29][30] which will bring about good catalytic activity due to metal-support interactions. In other words, Pt may be coordinated with oxygen-containing groups on supports to Atomic-scale utilization and coordination structure of Pt electrocatalyst is extremely crucial to decrease loading mass and maximize activity for hydrogen evolution reactions (HERs) and oxygen reduction reactions (ORRs). A novel atomic-scale (Pt-O x )-(Co-O y ) nonbonding active structure is designed and constructed by anchoring Pt single atoms and Co atomic clusters on the defective carbon derived from oxygen-rich coal tar pitch (CTP). The Pt loading mass is extremely low and only 0.56 wt%. A new nonbonding interaction phenomenon between Pt-O x and Co-O y is found a...

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Section: Synthesis and Structural Characterizationmentioning

confidence: 99%

Novel (Pt‐O_x)‐(Co‐O_y) Nonbonding Active Structures on Defective Carbon from Oxygen‐Rich Coal Tar Pitch for Efficient HER and ORR

et al. 2022

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“…However, the intermittency of renewable energy has brought challenges to the stable operation of power grids. As an effective way to stabilize the power fluctuations, the electrochemical energy storage technique has been widely used in renewable energy generation systems [4][5][6], of which a bidirectional DC-DC converter is the core equipment. Due to the low voltage stress, small passive components, and common ground between input and output terminals, the flying capacitor three-level topology has certain advantages in medium-and high-voltage energy storage systems (ESSs) [7,8].…”

Section: Introductionmentioning

confidence: 99%

Decoupled MPC Power Balancing Strategy for Coupled Inductor Flying Capacitor DC–DC Converter

Wei,

Bi,

Lan

et al. 2024

Applied Sciences

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A decoupled model predictive control (MPC) power balancing strategy for a coupled inductor-based flying capacitor DC–DC converter (FCDC) is a proposed to solve the power imbalance caused by the parameter differences in the coupled inductor. The decoupled mathematical model of coupled inductor FCDC is firstly derived by analyzing the converter operation state under various modes. On this basis, the control relationship between inductor current and flying capacitor (FC) voltage is redefined and an MPC power balance strategy based on the inductor current with single-step optimization is proposed. The proposed MPC strategy not only achieves decoupled power balancing control but also solves multi-objective dynamic optimization control of the inductor current and FC voltage, greatly reducing the computation load. A detailed theoretical analysis of the proposed strategy is presented and the balancing performance is effectively verified through the experiments.

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“…[1][2][3][4] However, these new energy sources have indirectness and uncertainty in the process of using them due to seasonal and time constraints, which greatly affects the efficiency of energy utilization. [5][6][7] Therefore, it is imperative to develop and design an energy storage and conversion system of high conversion efficiency and good stability, such as Zn-Air batteries (ZABs), fuel cells (FCs), and so on. [8][9][10] It is worth noting that there are still challenges in using these new energy technologies as they are highly dependent on a number of electrochemical reactions.…”

Section: Introductionmentioning

confidence: 99%

A Simultaneous Modulation Strategy to Construct High Dense and Accessible Co‐N₄ Sites for Promoting Oxygen Reduction Reaction in Zn–Air Battery

Xie,

Peng,

Sun

et al. 2024

Adv Funct Materials

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Transition metal‐nitrogen‐carbon single‐atom catalysts (M─N─C SACs) exhibit outstanding catalytic activity for the oxygen reduction reaction (ORR). However, these catalysts still face the dual challenges of low density and low utilization of active sites in practical applications. Hence, a simultaneous modulation strategy to construct high‐density and accessible Co‐N4 sites on nitrogen‐doped porous carbon (CoH SA/NC), is reported. As expected, the optimized CoH SA/NC catalyst exhibits superior ORR activity with a half‐wave potential value of 0.874 V, outperforming that of the benchmark Pt/C catalyst. Importantly, the mass activity and turnover frequency of CoH SA/NC are 14.7 and 13.3 times higher than that of low‐density Co single atom catalyst (CoL SA/NC), respectively. Structural characterization and density functional theory (DFT) reveal that the porous structure and the high dense Co‐N4 sites synergistically improve the ORR performance, in which the high dense Co‐N4 sites induced a redistribution of the d orbital, resulting in dz2 orbital has enough electron to interact with the OOH* specie, thereby facilitating the kinetic process of ORR. Moreover, CoH SA/NC‐based Zn–Air Battery (ZAB) also showed excellent device performance, including a high‐power density (191.7 mW cm−2), high specific capacity, and outstanding stability (250 h), significantly superior to benchmark Pt/C‐based ZABs.

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Honeycomb-like carbon for electrochemical energy storage and conversion

Cited by 23 publications

References 175 publications

Novel (Pt‐O_x)‐(Co‐O_y) Nonbonding Active Structures on Defective Carbon from Oxygen‐Rich Coal Tar Pitch for Efficient HER and ORR

Novel (Pt‐O_x)‐(Co‐O_y) Nonbonding Active Structures on Defective Carbon from Oxygen‐Rich Coal Tar Pitch for Efficient HER and ORR

Decoupled MPC Power Balancing Strategy for Coupled Inductor Flying Capacitor DC–DC Converter

A Simultaneous Modulation Strategy to Construct High Dense and Accessible Co‐N₄ Sites for Promoting Oxygen Reduction Reaction in Zn–Air Battery

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Honeycomb-like carbon for electrochemical energy storage and conversion

Cited by 23 publications

References 175 publications

Novel (Pt‐Ox)‐(Co‐Oy) Nonbonding Active Structures on Defective Carbon from Oxygen‐Rich Coal Tar Pitch for Efficient HER and ORR

Novel (Pt‐Ox)‐(Co‐Oy) Nonbonding Active Structures on Defective Carbon from Oxygen‐Rich Coal Tar Pitch for Efficient HER and ORR

Decoupled MPC Power Balancing Strategy for Coupled Inductor Flying Capacitor DC–DC Converter

A Simultaneous Modulation Strategy to Construct High Dense and Accessible Co‐N4 Sites for Promoting Oxygen Reduction Reaction in Zn–Air Battery

Contact Info

Product

Resources

About

Novel (Pt‐O_x)‐(Co‐O_y) Nonbonding Active Structures on Defective Carbon from Oxygen‐Rich Coal Tar Pitch for Efficient HER and ORR

Novel (Pt‐O_x)‐(Co‐O_y) Nonbonding Active Structures on Defective Carbon from Oxygen‐Rich Coal Tar Pitch for Efficient HER and ORR

A Simultaneous Modulation Strategy to Construct High Dense and Accessible Co‐N₄ Sites for Promoting Oxygen Reduction Reaction in Zn–Air Battery