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Annemie Bogaerts - One of the best experts on this subject based on the ideXlab platform.

  • Plasma Technology for CO2 Conversion: A Personal Perspective on Prospects and Gaps
    Frontiers in Energy Research, 2020
    Co-Authors: Annemie Bogaerts, Gabriele Centi
    Abstract:

    Plasma technology is gaining increasing interest for CO2 Conversion, because it can operate at mild conditions and it can store fluctuating renewable electricity into value-added compounds and renewable fuels. This perspective paper aims to provide a view on the future for non-specialists, who like to understand the role of plasma technology in the new scenario for sustainable and low-carbon energy and chemistry. It is thus prepared to give a personal view on future opportunities and challenges. First, we introduce the current state-of-the-art and the potential of plasma-based CO2 Conversion. Subsequently we discuss the challenges to overcome the current limitations and to apply plasma technology on a large scale. The final section discusses the general context and the potential benefits of plasma-based CO2 Conversion for our life and the impact on Climate Change. It also includes a brief analysis on the future scenario for energy and chemical production and how plasma technology may realize new paths for CO2 utilization.

  • plasma technology an emerging technology for energy storage
    ACS energy letters, 2018
    Co-Authors: Annemie Bogaerts, Erik C Neyts
    Abstract:

    Plasma technology is gaining increasing interest for gas Conversion applications, such as CO2 Conversion into value-added chemicals or renewable fuels, and N2 fixation from the air, to be used for the production of small building blocks for, e.g., mineral fertilizers. Plasma is generated by electric power and can easily be switched on/off, making it, in principle, suitable for using intermittent renewable electricity. In this Perspective article, we explain why plasma might be promising for this application. We briefly present the most common types of plasma reactors with their characteristic features, illustrating why some plasma types exhibit better energy efficiency than others. We also highlight current research in the fields of CO2 Conversion (including the combined Conversion of CO2 with CH4, H2O, or H2) as well as N2 fixation (for NH3 or NOx synthesis). Finally, we discuss the major limitations and steps to be taken for further improvement.

  • Supersonic Microwave Plasma: Potential and Limitations for Energy-Efficient CO2 Conversion
    2018
    Co-Authors: Vincent Vermeiren, Annemie Bogaerts
    Abstract:

    Supersonic flows provide a high thermodynamic nonequilibrium, which is crucial for energy-efficient Conversion of CO2 in microwave plasmas and are therefore of great interest. However, the effect of the flow on the chemical reactions is poorly understood. In this work, we present a combined flow and plasma chemical kinetics model of a microwave CO2 plasma in a Laval nozzle setup. The effects of the flow field on the different dissociation and recombination mechanisms, the vibrational distribution, and the vibrational transfer mechanism are discussed. In addition, the effect of experimental parameters, like position of power deposition, outlet pressure, and specific energy input, on the CO2 Conversion and energy efficiency is examined. The short residence time of the gas in the plasma region, the shockwave, and the maximum critical heat, and thus power, that can be added to the flow to avoid thermal choking are the main obstacles to reaching high energy efficiencies

  • Plasma technology - a novel solution for CO2 Conversion?
    Chemical Society Reviews, 2017
    Co-Authors: Ramses Snoeckx, Annemie Bogaerts
    Abstract:

    CO2 Conversion into value-added chemicals and fuels is considered as one of the great challenges of the 21st century. Due to the limitations of the traditional thermal approaches, several novel technologies are being developed. One promising approach in this field, which has received little attention to date, is plasma technology. Its advantages include mild operating conditions, easy upscaling, and gas activation by energetic electrons instead of heat. This allows thermodynamically difficult reactions, such as CO2 splitting and the dry reformation of methane, to occur with reasonable energy cost. In this review, after exploring the traditional thermal approaches, we have provided a brief overview of the fierce competition between various novel approaches in a quest to find the most effective and efficient CO2 Conversion technology. This is needed to critically assess whether plasma technology can be successful in an already crowded arena. The following questions need to be answered in this regard: are there key advantages to using plasma technology over other novel approaches, and if so, what is the flip side to the use of this technology? Can plasma technology be successful on its own, or can synergies be achieved by combining it with other technologies? To answer these specific questions and to evaluate the potentials and limitations of plasma technology in general, this review presents the current state-of-the-art and a critical assessment of plasma-based CO2 Conversion, as well as the future challenges for its practical implementation.

  • CO2 Conversion by plasma technology insights from modeling the plasma chemistry and plasma reactor design
    Plasma Sources Science and Technology, 2017
    Co-Authors: Annemie Bogaerts, Ramses Snoeckx, Antonin Berthelot, Stijn Heijkers, St Kolev, S Sun, Georgi Trenchev, K Van Laer, Weizong Wang
    Abstract:

    In recent years there is growing interest in the use of plasma technology for CO2 Conversion. To improve this application, a good insight in the underlying mechanisms is of great importance. This can be obtained from modeling of the detailed plasma chemistry, to understand the chemical reaction pathways leading to CO2 Conversion (either in pure form or mixed with another gas). Moreover, in practice several plasma reactor types are being investigated for CO2 Conversion, so in addition it is essential to model these reactor geometries, in order to be able to improve their design, and to achieve the most energy efficient CO2 Conversion. Modeling the detailed plasma chemistry of CO2 Conversion in complex reactors is, however, very time-consuming. This problem can be overcome by using a combination of two different types of models. 0D chemical reaction kinetics models are very suitable for describing the detailed plasma chemistry, while the characteristic features of different reactor geometries can be studied by 2D or 3D fluid models. The latter can in first instance be developed in argon or helium, with a simple chemistry, to limit the calculation time, but the ultimate aim is to implement the more complex CO2 chemistry in these models. In the present paper, examples will be given of both 0D plasma chemistry models and 2D and 3D fluid models for the most common plasma reactors used for CO2 Conversion, to emphasize the complementarity of both approaches. Furthermore, based on the modeling insights, the paper discusses the possibilities and limitations of plasma-based CO2 Conversion in the different types of plasma reactors, and what would be needed to make further progress in this field.

Ramses Snoeckx - One of the best experts on this subject based on the ideXlab platform.

  • Plasma technology - a novel solution for CO2 Conversion?
    Chemical Society Reviews, 2017
    Co-Authors: Ramses Snoeckx, Annemie Bogaerts
    Abstract:

    CO2 Conversion into value-added chemicals and fuels is considered as one of the great challenges of the 21st century. Due to the limitations of the traditional thermal approaches, several novel technologies are being developed. One promising approach in this field, which has received little attention to date, is plasma technology. Its advantages include mild operating conditions, easy upscaling, and gas activation by energetic electrons instead of heat. This allows thermodynamically difficult reactions, such as CO2 splitting and the dry reformation of methane, to occur with reasonable energy cost. In this review, after exploring the traditional thermal approaches, we have provided a brief overview of the fierce competition between various novel approaches in a quest to find the most effective and efficient CO2 Conversion technology. This is needed to critically assess whether plasma technology can be successful in an already crowded arena. The following questions need to be answered in this regard: are there key advantages to using plasma technology over other novel approaches, and if so, what is the flip side to the use of this technology? Can plasma technology be successful on its own, or can synergies be achieved by combining it with other technologies? To answer these specific questions and to evaluate the potentials and limitations of plasma technology in general, this review presents the current state-of-the-art and a critical assessment of plasma-based CO2 Conversion, as well as the future challenges for its practical implementation.

  • CO2 Conversion by plasma technology insights from modeling the plasma chemistry and plasma reactor design
    Plasma Sources Science and Technology, 2017
    Co-Authors: Annemie Bogaerts, Ramses Snoeckx, Antonin Berthelot, Stijn Heijkers, St Kolev, S Sun, Georgi Trenchev, K Van Laer, Weizong Wang
    Abstract:

    In recent years there is growing interest in the use of plasma technology for CO2 Conversion. To improve this application, a good insight in the underlying mechanisms is of great importance. This can be obtained from modeling of the detailed plasma chemistry, to understand the chemical reaction pathways leading to CO2 Conversion (either in pure form or mixed with another gas). Moreover, in practice several plasma reactor types are being investigated for CO2 Conversion, so in addition it is essential to model these reactor geometries, in order to be able to improve their design, and to achieve the most energy efficient CO2 Conversion. Modeling the detailed plasma chemistry of CO2 Conversion in complex reactors is, however, very time-consuming. This problem can be overcome by using a combination of two different types of models. 0D chemical reaction kinetics models are very suitable for describing the detailed plasma chemistry, while the characteristic features of different reactor geometries can be studied by 2D or 3D fluid models. The latter can in first instance be developed in argon or helium, with a simple chemistry, to limit the calculation time, but the ultimate aim is to implement the more complex CO2 chemistry in these models. In the present paper, examples will be given of both 0D plasma chemistry models and 2D and 3D fluid models for the most common plasma reactors used for CO2 Conversion, to emphasize the complementarity of both approaches. Furthermore, based on the modeling insights, the paper discusses the possibilities and limitations of plasma-based CO2 Conversion in the different types of plasma reactors, and what would be needed to make further progress in this field.

  • plasma based Conversion of CO2 current status and future challenges
    Faraday Discussions, 2015
    Co-Authors: Annemie Bogaerts, Tomas Kozak, Koen Van Laer, Ramses Snoeckx
    Abstract:

    This paper discusses our recent results on plasma-based CO2 Conversion, obtained by a combination of experiments and modeling, for a dielectric barrier discharge (DBD), a microwave plasma and a packed bed DBD reactor. The results illustrate that plasma technology is quite promising for CO2 Conversion, but more research is needed to better understand the underlying mechanisms and to further improve the capabilities.

  • CO2 Conversion in a microwave plasma reactor in the presence of n2 elucidating the role of vibrational levels
    Journal of Physical Chemistry C, 2015
    Co-Authors: Stijn Heijkers, Ramses Snoeckx, Tomas Kozak, Tiago Silva, Thomas Godfroid, Nikolay Britun, Rony Snyders, Annemie Bogaerts
    Abstract:

    A chemical kinetics model is developed for a CO2/N2 microwave plasma, focusing especially on the vibrational levels of both CO2 and N2. The model is used to calculate the CO2 and N2 Conversion as well as the energy efficiency of CO2 Conversion for different power densities and for N2 fractions in the CO2/N2 gas mixture ranging from 0 to 90%. The calculation results are compared with measurements, and agreements within 23% and 33% are generally found for the CO2 Conversion and N2 Conversion, respectively. To explain the observed trends, the destruction and formation processes of both CO2 and N2 are analyzed, as well as the vibrational distribution functions of both CO2 and N2. The results indicate that N2 contributes in populating the lower asymmetric levels of CO2, leading to a higher absolute CO2 Conversion upon increasing N2 fraction. However, the effective CO2 Conversion drops because there is less CO2 initially present in the gas mixture; thus, the energy efficiency also drops with rising N2 fraction.

Shizhang Qiao - One of the best experts on this subject based on the ideXlab platform.

  • cocatalysts in semiconductor based photocatalytic CO2 reduction achievements challenges and opportunities
    Advanced Materials, 2018
    Co-Authors: Jingrun Ran, Mietek Jaroniec, Shizhang Qiao
    Abstract:

    Ever-increasing fossil-fuel combustion along with massive CO2 emissions has aroused a global energy crisis and climate change. Photocatalytic CO2 reduction represents a promising strategy for clean, cost-effective, and environmentally friendly Conversion of CO2 into hydrocarbon fuels by utilizing solar energy. This strategy combines the reductive half-reaction of CO2 Conversion with an oxidative half reaction, e.g., H2 O oxidation, to create a carbon-neutral cycle, presenting a viable solution to global energy and environmental problems. There are three pivotal processes in photocatalytic CO2 Conversion: (i) solar-light absorption, (ii) charge separation/migration, and (iii) catalytic CO2 reduction and H2 O oxidation. While significant progress is made in optimizing the first two processes, much less research is conducted toward enhancing the efficiency of the third step, which requires the presence of cocatalysts. In general, cocatalysts play four important roles: (i) boosting charge separation/transfer, (ii) improving the activity and selectivity of CO2 reduction, (iii) enhancing the stability of photocatalysts, and (iv) suppressing side or back reactions. Herein, for the first time, all the developed CO2 -reduction cocatalysts for semiconductor-based photocatalytic CO2 Conversion are summarized, and their functions and mechanisms are discussed. Finally, perspectives in this emerging area are provided.

Buxing Han - One of the best experts on this subject based on the ideXlab platform.

  • photocatalytic CO2 transformation to ch4 by ag pd bimetals supported on n doped tio2 nanosheet
    ACS Applied Materials & Interfaces, 2018
    Co-Authors: Dongxing Tan, Jianling Zhang, Jinbiao Shi, Bingxing Zhang, Xiuniang Tan, Fanyu Zhang, Lifei Liu, Dan Shao, Buxing Han
    Abstract:

    To develop photocatalysts with desirable compositions and structures for improving the efficiency and selectivity of CO2 Conversion to CH4 under mild conditions is of great importance. Here, we design an effective photocatalyst of bimetal (Ag/Pd) nanoalloys supported on nitrogen-doped TiO2 nanosheet for CO2 Conversion. Such a novel photocatalyst combines multiple advantages of abundant Ti3+ ions, oxygen vacancies, and substitutional nitrogen that are favorable for catalyzing CO2 reduction. It was found that CO2 could be efficiently transformed to CH4 under mild conditions, i.e., in aqueous solution and at atmospheric pressure and room temperature. The maximum production rate of CH4 can reach 79.0 μmol g–1 h–1. Moreover, the Ag/Pd bimetals supported on N-doped TiO2 nanosheet exhibit high selectivity to CH4. The as-synthesized photocatalyst can be well recycled for CO2 reduction.

  • Photocatalytic CO2 Transformation to CH4 by Ag/Pd Bimetals Supported on N‑Doped TiO2 Nanosheet
    2018
    Co-Authors: Dongxing Tan, Jianling Zhang, Jinbiao Shi, Bingxing Zhang, Xiuniang Tan, Fanyu Zhang, Lifei Liu, Dan Shao, Buxing Han
    Abstract:

    To develop photocatalysts with desirable compositions and structures for improving the efficiency and selectivity of CO2 Conversion to CH4 under mild conditions is of great importance. Here, we design an effective photocatalyst of bimetal (Ag/Pd) nanoalloys supported on nitrogen-doped TiO2 nanosheet for CO2 Conversion. Such a novel photocatalyst combines multiple advantages of abundant Ti3+ ions, oxygen vacancies, and substitutional nitrogen that are favorable for catalyzing CO2 reduction. It was found that CO2 could be efficiently transformed to CH4 under mild conditions, i.e., in aqueous solution and at atmospheric pressure and room temperature. The maximum production rate of CH4 can reach 79.0 μmol g–1 h–1. Moreover, the Ag/Pd bimetals supported on N-doped TiO2 nanosheet exhibit high selectivity to CH4. The as-synthesized photocatalyst can be well recycled for CO2 reduction

Markus Antonietti - One of the best experts on this subject based on the ideXlab platform.

  • improving artificial photosynthesis over carbon nitride by gas liquid solid interface management for full light induced CO2 reduction to c1 and c2 fuels and o2
    Chemsuschem, 2020
    Co-Authors: Kai Xiao, Bei Cheng, Jiaguo Yu, Lei Jiang, Markus Antonietti
    Abstract:

    The activity and selectivity of simple photocatalysts for CO2 reduction remain limited by the insufficient photophysics of the catalysts, as well as the low solubility and slow mass transport of gas molecules in/through aqueous solution. In this study, these limitations are overcome by constructing a triphasic photocatalytic system, in which polymeric carbon nitride (CN) is immobilized onto a hydrophobic substrate, and the photocatalytic reduction reaction occurs at a gas-liquid-solid (CO2 -water-catalyst) triple interface. CN anchored onto the surface of a hydrophobic substrate exhibits an approximately 7.2-fold enhancement in total CO2 Conversion, with a rate of 415.50 mumol m(-2) h(-1) under simulated solar light irradiation. This value corresponds to an overall photosynthetic efficiency for full water-CO2 Conversion of 0.33 %, which is very close to biological systems. A remarkable enhancement of direct C2 hydrocarbon production and a high CO2 Conversion selectivity of 97.7 % are observed. Going from water oxidation to phosphate oxidation, the quantum yield is increased to 1.28 %.