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Zhongwei Chen - One of the best experts on this subject based on the ideXlab platform.

  • synergistic Bifunctional Catalyst design based on perovskite oxide nanoparticles and intertwined carbon nanotubes for rechargeable zinc air battery applications
    ACS Applied Materials & Interfaces, 2015
    Co-Authors: Dong Un Lee, Hey Woong Park, Moon Gyu Park, Vugar Ismayilov, Zhongwei Chen
    Abstract:

    Advanced morphology of intertwined core–corona structured Bifunctional Catalyst (IT-CCBC) is introduced where perovskite lanthanum nickel oxide nanoparticles (LaNiO3 NP) are encapsulated by high surface area network of nitrogen-doped carbon nanotubes (NCNT) to produce highly active and durable Bifunctional Catalyst for rechargeable metal–air battery applications. The unique composite morphology of IT-CCBC not only enhances the charge transport property by providing rapid electron-conduction pathway but also facilitates in diffusion of hydroxyl and oxygen reactants through the highly porous framework. Confirmed by electrochemical half-cell testing, IT-CCBC in fact exhibits very strong synergy between LaNiO3 NP and NCNT demonstrating Bifunctionality with significantly improved catalytic activities of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Furthermore, when compared to the state-of-art Catalysts, IT-CCBC outperforms Pt/C and Ir/C in terms of ORR and OER, respectively, and shows ...

  • Synergistic Bifunctional Catalyst Design based on Perovskite Oxide Nanoparticles and Intertwined Carbon Nanotubes for Rechargeable Zinc–Air Battery Applications
    2015
    Co-Authors: Dong Un Lee, Hey Woong Park, Moon Gyu Park, Vugar Ismayilov, Zhongwei Chen
    Abstract:

    Advanced morphology of intertwined core–corona structured Bifunctional Catalyst (IT-CCBC) is introduced where perovskite lanthanum nickel oxide nanoparticles (LaNiO3 NP) are encapsulated by high surface area network of nitrogen-doped carbon nanotubes (NCNT) to produce highly active and durable Bifunctional Catalyst for rechargeable metal–air battery applications. The unique composite morphology of IT-CCBC not only enhances the charge transport property by providing rapid electron-conduction pathway but also facilitates in diffusion of hydroxyl and oxygen reactants through the highly porous framework. Confirmed by electrochemical half-cell testing, IT-CCBC in fact exhibits very strong synergy between LaNiO3 NP and NCNT demonstrating Bifunctionality with significantly improved catalytic activities of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Furthermore, when compared to the state-of-art Catalysts, IT-CCBC outperforms Pt/C and Ir/C in terms of ORR and OER, respectively, and shows improved electrochemical stability compared to them after cycle degradation testing. The practicality of the Catalyst is corroborated by testing in a realistic rechargeable zinc–air battery utilizing atmospheric air in ambient conditions, where IT-CCBC demonstrates superior charge and discharge voltages and long-term cycle stability with virtually no battery voltage fading. These improved electrochemical properties of the Catalyst are attributed to the nanosized dimensions of LaNiO3 NP controlled by simple hydrothermal technique, which enables prolific growth of and encapsulation by highly porous NCNT network. The excellent electrochemical results presented in this study highlight IT-CCBC as highly efficient and commercially viable Bifunctional Catalyst for rechargeable metal–air battery applications

  • manganese dioxide nanotube and nitrogen doped carbon nanotube based composite Bifunctional Catalyst for rechargeable zinc air battery
    Electrochimica Acta, 2012
    Co-Authors: Zhu Chen, Aiping Yu, Raihan Ahmed, Haijiang Wang, Hui Li, Zhongwei Chen
    Abstract:

    Abstract A composite Bifunctional Catalyst (MnO2–NCNT) was prepared from manganese dioxide (MnO2) nanotubes and nitrogen-doped carbon nanotubes (NCNT) for the purpose of oxygen reduction (ORR) and evolution (OER) catalysis in the rechargeable zinc-air battery. From the half cell test, the MnO2–NCNT composite illustrated excellent activities towards ORR and OER in alkaline conditions. Based on the battery test, the composite Catalyst displayed outstanding discharge and charge performance while maintaining good stability. In both cases, the marked performance improvements from MnO2–NCNT compared favourably to the NCNT and MnO2, which are the constituents of the composite. In particular, MnO2–NCNT exhibited improved half wave potential by 220 mV compared to MnO2 and much superior OER stability compared to NCNT based on the rotating ring disk voltammetry results. According to battery test, MnO2–NCNT decrease the battery resistance by 34% and concurrently improved the durability, discharge and charge performance in comparison to the MnO2 nanotubes.

  • manganese dioxide nanotube and nitrogen doped carbon nanotube based composite Bifunctional Catalyst for rechargeable zinc air battery
    Electrochimica Acta, 2012
    Co-Authors: Zhu Chen, Raihan Ahmed, Haijiang Wang, Zhongwei Chen
    Abstract:

    Abstract A composite Bifunctional Catalyst (MnO2–NCNT) was prepared from manganese dioxide (MnO2) nanotubes and nitrogen-doped carbon nanotubes (NCNT) for the purpose of oxygen reduction (ORR) and evolution (OER) catalysis in the rechargeable zinc-air battery. From the half cell test, the MnO2–NCNT composite illustrated excellent activities towards ORR and OER in alkaline conditions. Based on the battery test, the composite Catalyst displayed outstanding discharge and charge performance while maintaining good stability. In both cases, the marked performance improvements from MnO2–NCNT compared favourably to the NCNT and MnO2, which are the constituents of the composite. In particular, MnO2–NCNT exhibited improved half wave potential by 220 mV compared to MnO2 and much superior OER stability compared to NCNT based on the rotating ring disk voltammetry results. According to battery test, MnO2–NCNT decrease the battery resistance by 34% and concurrently improved the durability, discharge and charge performance in comparison to the MnO2 nanotubes.

  • highly active and durable core corona structured Bifunctional Catalyst for rechargeable metal air battery application
    Nano Letters, 2012
    Co-Authors: Zhu Chen, Aiping Yu, Haijiang Wang, Hui Li, Drew Higgins, Zhongwei Chen
    Abstract:

    A new class of core–corona structured Bifunctional Catalyst (CCBC) consisting of lanthanum nickelate centers supporting nitrogen-doped carbon nanotubes (NCNT) has been developed for rechargeable metal–air battery application. The nanostructured design of the Catalyst allows the core and corona to catalyze the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR), respectively. These materials displayed exemplary OER and ORR activity through half-cell testing, comparable to state of the art commercial lanthanum nickelate (LaNiO3) and carbon-supported platinum (Pt/C), with added Bifunctional capabilities allowing metal–air battery rechargeability. LaNiO3 and Pt/C are currently the most accepted benchmark electroCatalyst materials for the OER and ORR, respectively; thus with comparable activity toward both of these reactions, CCBC are presented as a novel, inexpensive Catalyst component for the cathode of rechargeable metal–air batteries. Moreover, after full-range degradation testing (FDT) CCB...

Peyman Keshavarz - One of the best experts on this subject based on the ideXlab platform.

  • production of hydrogen rich syngas using zr modified ca co Bifunctional Catalyst sorbent in chemical looping steam methane reforming
    Applied Energy, 2017
    Co-Authors: S Akbariemadabadi, M R Rahimpour, A Hafizi, Peyman Keshavarz
    Abstract:

    Abstract High purity H 2 could be produced through modified chemical looping steam methane reforming (CL-SMR) process using calcium as an essential component in the structure of Bifunctional Catalyst-sorbents. Herein, we present an effective approach to the production of high purity hydrogen in chemical looping reforming of methane via modification of a Bifunctional Ca-Co-Zr Catalyst-sorbent. The synthesis of the samples including pure Ca, Ca-Co and zirconium modified Ca-Co with different molar ratios was performed using co-precipitation method. The influence of reaction variables such as steam to carbon molar ratio (S/C = 1–5), reaction temperature (500–750 °C) and lifetime of the samples are investigated on methane conversion and hydrogen yield. Moreover, Ca/Co mass ratio (0.11–9) is optimized and subsequently, different amounts of zirconium promoter (mass ratio = 2.25–18) are added to improve the Bifunctional Catalyst-sorbent structure. The characterization of samples was performed using XRD, FESEM, BET and EDX techniques. It is found that the addition of zirconium to the sample could improve the textural features and stability of Bifunctional Catalyst-sorbent. The results reveal that Ca-Co-Zr (via mass ratios of Ca Co = 9 and Ca Zr = 4.5 ) exhibits the highest catalytic activity among all tested samples and shows 98.3% methane conversion and 84.5% hydrogen yield at 700 °C. The cyclic life time results at 700 °C indicated that the Ca-Co-Zr (9,4.5) Bifunctional Catalyst-sorbent remained stable up to 16 cycles, while non-promoted samples showed fast deactivation after about 10 redox cycles. The coke formation is inhibited, while the reaction pathway changes to a combined reaction. In summary, the obtained results show the suitable efficiency of the synthesized Catalyst in the modified CL-SMR process.

  • promotion of ca co Bifunctional Catalyst sorbent with yttrium for hydrogen production in modified chemical looping steam methane reforming process
    Catalysts, 2017
    Co-Authors: S Akbariemadabadi, M R Rahimpour, A Hafizi, Peyman Keshavarz
    Abstract:

    In this study, the application of a calcium-based Bifunctional Catalyst/sorbent is investigated in modified chemical looping steam methane reforming (CLSMR) process for in situ CO2 sorption and H2 production. The yttrium promoted Ca-Co samples were synthesized and applied as Bifunctional Catalysts/sorbent. The influence of reduction temperature (500–750 °C), Ca/Co and Ca/Y ratios (1.5–∞ and 3–18, respectively) and Catalyst life time are determined in CLSMR process. The physicochemical transformation of fresh, used and regenerated samples after 16 redox cycles are determined using X-ray powder diffraction (XRD), N2 adsorption–desorption, field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX) and transmission electron microscopy (TEM) techniques. The effect of yttrium promoter on the structure of Catalyst and regeneration step on the reversibility of Bifunctional Catalyst/sorbent was two important factors. The characterization results revealed that the presence of yttrium in the structure of Ca-9Co sample could improve the morphology and textural properties of Catalyst/sorbents. The suitable reversibility of Bifunctional Catalyst/sorbents during the repeated cycles is confirmed by characterization of calcined samples. The Ca-9Co-4.5Y as optimal Catalyst illustrated superior performance and stability. It showed about 95.8% methane conversion and 82.9% hydrogen yield at 700 °C and stable activity during 16 redox cycles.

Zhu Chen - One of the best experts on this subject based on the ideXlab platform.

  • manganese dioxide nanotube and nitrogen doped carbon nanotube based composite Bifunctional Catalyst for rechargeable zinc air battery
    Electrochimica Acta, 2012
    Co-Authors: Zhu Chen, Aiping Yu, Raihan Ahmed, Haijiang Wang, Hui Li, Zhongwei Chen
    Abstract:

    Abstract A composite Bifunctional Catalyst (MnO2–NCNT) was prepared from manganese dioxide (MnO2) nanotubes and nitrogen-doped carbon nanotubes (NCNT) for the purpose of oxygen reduction (ORR) and evolution (OER) catalysis in the rechargeable zinc-air battery. From the half cell test, the MnO2–NCNT composite illustrated excellent activities towards ORR and OER in alkaline conditions. Based on the battery test, the composite Catalyst displayed outstanding discharge and charge performance while maintaining good stability. In both cases, the marked performance improvements from MnO2–NCNT compared favourably to the NCNT and MnO2, which are the constituents of the composite. In particular, MnO2–NCNT exhibited improved half wave potential by 220 mV compared to MnO2 and much superior OER stability compared to NCNT based on the rotating ring disk voltammetry results. According to battery test, MnO2–NCNT decrease the battery resistance by 34% and concurrently improved the durability, discharge and charge performance in comparison to the MnO2 nanotubes.

  • manganese dioxide nanotube and nitrogen doped carbon nanotube based composite Bifunctional Catalyst for rechargeable zinc air battery
    Electrochimica Acta, 2012
    Co-Authors: Zhu Chen, Raihan Ahmed, Haijiang Wang, Zhongwei Chen
    Abstract:

    Abstract A composite Bifunctional Catalyst (MnO2–NCNT) was prepared from manganese dioxide (MnO2) nanotubes and nitrogen-doped carbon nanotubes (NCNT) for the purpose of oxygen reduction (ORR) and evolution (OER) catalysis in the rechargeable zinc-air battery. From the half cell test, the MnO2–NCNT composite illustrated excellent activities towards ORR and OER in alkaline conditions. Based on the battery test, the composite Catalyst displayed outstanding discharge and charge performance while maintaining good stability. In both cases, the marked performance improvements from MnO2–NCNT compared favourably to the NCNT and MnO2, which are the constituents of the composite. In particular, MnO2–NCNT exhibited improved half wave potential by 220 mV compared to MnO2 and much superior OER stability compared to NCNT based on the rotating ring disk voltammetry results. According to battery test, MnO2–NCNT decrease the battery resistance by 34% and concurrently improved the durability, discharge and charge performance in comparison to the MnO2 nanotubes.

  • highly active and durable core corona structured Bifunctional Catalyst for rechargeable metal air battery application
    Nano Letters, 2012
    Co-Authors: Zhu Chen, Aiping Yu, Haijiang Wang, Hui Li, Drew Higgins, Zhongwei Chen
    Abstract:

    A new class of core–corona structured Bifunctional Catalyst (CCBC) consisting of lanthanum nickelate centers supporting nitrogen-doped carbon nanotubes (NCNT) has been developed for rechargeable metal–air battery application. The nanostructured design of the Catalyst allows the core and corona to catalyze the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR), respectively. These materials displayed exemplary OER and ORR activity through half-cell testing, comparable to state of the art commercial lanthanum nickelate (LaNiO3) and carbon-supported platinum (Pt/C), with added Bifunctional capabilities allowing metal–air battery rechargeability. LaNiO3 and Pt/C are currently the most accepted benchmark electroCatalyst materials for the OER and ORR, respectively; thus with comparable activity toward both of these reactions, CCBC are presented as a novel, inexpensive Catalyst component for the cathode of rechargeable metal–air batteries. Moreover, after full-range degradation testing (FDT) CCB...

  • highly active and durable core corona structured Bifunctional Catalyst for rechargeable metal air battery application
    Nano Letters, 2012
    Co-Authors: Zhu Chen, Haijiang Wang, Drew Higgins, Zhongwei Chen
    Abstract:

    A new class of core-corona structured Bifunctional Catalyst (CCBC) consisting of lanthanum nickelate centers supporting nitrogen-doped carbon nanotubes (NCNT) has been developed for rechargeable metal-air battery application. The nanostructured design of the Catalyst allows the core and corona to catalyze the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR), respectively. These materials displayed exemplary OER and ORR activity through half-cell testing, comparable to state of the art commercial lanthanum nickelate (LaNiO(3)) and carbon-supported platinum (Pt/C), with added Bifunctional capabilities allowing metal-air battery rechargeability. LaNiO(3) and Pt/C are currently the most accepted benchmark electroCatalyst materials for the OER and ORR, respectively; thus with comparable activity toward both of these reactions, CCBC are presented as a novel, inexpensive Catalyst component for the cathode of rechargeable metal-air batteries. Moreover, after full-range degradation testing (FDT) CCBC retained excellent activity, retaining 3 and 13 times greater ORR and OER current upon comparison to state of the art Pt/C. Zinc-air battery performances of CCBC is in good agreement with the half-cell experiments with this Bifunctional electroCatalyst displaying high activity and stability during battery discharge, charge, and cycling processes. Owing to its outstanding performance toward both the OER and ORR, comparable with the highest performing commercial Catalysts to date for each of the respective reaction, coupled with high stability and rechargeability, CCBC is presented as a novel class of Bifunctional Catalyst material that is very applicable to future generation rechargeable metal-air batteries.

Guy B Marin - One of the best experts on this subject based on the ideXlab platform.

  • Catalyst-assisted chemical looping auto-thermal dry reforming: Spatial structuring effects on process efficiency
    Applied Catalysis B: Environmental, 2018
    Co-Authors: Jiawei Hu, Vladimir V. Galvita, Hilde Poelman, Christophe Detavernier, Guy B Marin
    Abstract:

    Catalyst-assisted chemical looping auto-thermal dry reforming (CCAR) is an environment-friendly energy conversion process, performed over a reactor bed with double function, composed of a Catalyst and an oxygen storage material (OSM). It converts CH4 and CO2 into industrial syngas, while simultaneously utilizing CO2 from the atmosphere. Two reactor bed configurations were tested, based on the concept of double- and single-zone distribution of Catalyst and OSM. Combinations of core-shell structured materials were applied, such as Ni/ZrO2@ZrO2 Catalyst, Fe2O3/ZrO2@ZrO2 OSM and Fe/Zr@Zr-Ni@Zr Bifunctional Catalyst, to assess the spatial structuring at both reactor bed and pellet scale. Samples from different reactor beds were characterized before and after use by ex- or in-situ XRD, N2 adsorption, XPS and STEM-EDX. 25 redox cycles of CCAR were performed to investigate the effect of spatial structuring on the activity and stability. The Fe/Zr@Zr-Ni@Zr Bifunctional Catalyst possesses higher activity and stability for catalytic CH4 conversion in the reduction half-cycle than the Ni/ZrO2@ZrO2 Catalyst due to its small Ni particle size (

Jialu Zhang - One of the best experts on this subject based on the ideXlab platform.