Magnesium–sulfur batteries are an emerging technology. With their elevated theoretical energy density, enhanced safety, and cost-efficiency, they have the ability to transform the energy storage market. This review investigates the obstacles and progress made in the field of electrolytes which are especially designed for magnesium–sulfur batteries. The primary focus of the review lies in identifying electrolytes that can facilitate the reversible electroplating and stripping of Mg2+ ions whilst maintaining compatibility with sulfur cathodes and other battery components. The review also addresses the critical issue of managing the shuttle effect on soluble magnesium polysulfide by looking at the innovative engineering methods used at the sulfur cathode’s interface and in the microstructure design, both of which can enhance the reaction kinetics and overall battery efficiency. This review emphasizes the significance of reaction mechanism analysis from the recent studies on magnesium–sulfur batteries. Through analysis of the insights proposed in the latest literature, this review identifies the gaps in the current research and suggests future directions which can enhance the electrochemical performance of Mg-S batteries. Our analysis highlights the importance of innovative electrolyte solutions and provides a deeper understanding of the reaction mechanisms in order to overcome the existing barriers and pave the way for the practical application of Mg-S battery technology.

Biomass gasification is a promising process for producing syngas, which is widely used in various industrial processes. However, the presence of tar in syngas poses a significant challenge to biomass gasification due to the difficulties in its removal and potential downstream issues, such as clogging, slagging, and corrosion. Extensive efforts have been made to address this challenge through catalytic tar removal using various catalysts, generating a vast amount of experimental data. Processing this large dataset and gaining new insights into process optimization requires the development of efficient data analysis methods. In this study, a comprehensive database was built, encompassing a total of 584 data points and 14 input parameters collected from literature published between 2005 and 2020. Machine learning algorithms were then trained using this dataset to predict and optimize the catalytic steam reforming of biomass tar. The predicted results were found to agree well with the experimental data. The results show that the reaction temperature is the most important process parameter, with the highest relative importance of 0.24, followed by the support (0.16), additive (0.12), nickel (Ni) loading (0.08), and calcination temperature (0.07), among the 14 input parameters. This work has proposed optimal ranges for the reaction temperature (600-700 degrees C), Ni loading (5-15 wt%), and calcination temperature (500-650 degrees C). Furthermore, it was found that a larger specific surface area and higher Ni dispersion are two critical factors for selecting additives and supports. This study provides insights into key parameters for optimizing the catalytic steam reforming of biomass tar, enabling enhanced efficiency and effectiveness in biomass gasification processes.

With a massive expansion in natural gas deposits, methane conversion has been attracting increasing attention. However, due to the robust C–H bond (434 kJ/mol) in CH4, elevated temperatures (>1000 °C) are typically required to activate CH4 in the conventional thermal chemical process, resulting in a reduced energy efficiency and high capital costs. Nonthermal plasma (NTP) technology has recently emerged as an attractive process for CH4 conversion at low temperatures and atmospheric pressure. In NTP, the inert CH4 molecules can be activated into the corresponding radicals, excited species, and ions by colliding with high-energy electrons under mild conditions. Besides, plasma can be easily switched on and off, allowing for flexible integration with renewable electricity. Through this chapter, we will introduce the fundamentals of plasma-assisted CH4 conversion and highlight the recent advances in this field, including the effects of plasma reactors, operating parameters, and catalysts on two typical CH4 conversion processes: nonoxidative coupling of methane and methane pyrolysis. The current challenges and future perspectives in this emerging area will also be discussed.

Syngas is a crucial feedstock for a number of key chemicals via the Fisher-Tropsch synthesis process. Currently, syngas is primarily produced via a thermal chemical process using fossil fuel-based feedstocks such as oil and coal, incurring high CO2 emissions, therefore developing new and sustainable processes using renewable energy is critical to achieve net zero. The use of non-thermal plasma (NTP) appears to be a promising technology for syngas generation from methane at low temperatures and atmospheric pressure. Through this chapter, we will introduce three promising reactions for the generation of syngas from methane in NTP (dry reforming of methane (DRM), steam reforming of methane (SMR), and partial oxidation of methane (POM)). This chapter will highlight the recent advances in this field, including the effects of plasma reactors, operating parameters, and catalysts. Furthermore, the current challenges and future perspectives in this emerging area will also be discussed in the conclusion of this chapter.

Biomass is considered as one of the most essential renewable energy sources for both mitigating global climate change and matching the rapidly increasing energy demands of the world's population. Biomass gasification produces syngas (H2 and CO) with a very high calorific value. This syngas can be used for production of high-value chemicals, fuels, heat, and electricity allowing biomass to replace a range of fossil fuel technologies with a sustainable and green process. However, the syngas produced from biomass gasification contains a range of problematic contaminants, particularly, tars. The high percentage of tars can cause blockages and deterioration preventing biomass technology from being commercialized, and their effective removal is one of the key challenges facing the bioenergy industry. The use of nonthermal plasma for the destruction and removal of tars is a promising and emerging technology for allowing the delivery of clean and high-quality syngas. In this book chapter, we have reviewed the recent progress and advances in the use of nonthermal plasma for syngas cleaning. The combination of nonthermal plasma and catalysis for syngas cleaning and tar reforming has also been summarized. Our perspectives on future of this emerging area have also been discussed.

A global transition to a hydrogen economy requires widespread adoption of clean hydrogen energy. Methane cracking is one of the most viable technologies for producing clean hydrogen, nearing the ultimate zero-carbon-emissions targets. While major progress has been made in the lab-scale development of high-performance reactors and catalysts for methane pyrolysis, research focusing on industry-relevant scale and process conditions is in its infancy. Herein, recent advances in fundamental and applied research in methane pyrolysis are critically examined, focusing on physico-chemical mechanisms to achieve energy-efficient, low-carbon-emission, scalable processes. The highlighted recent efforts to bridge the gap between laboratory research and industrial applications reveal rapid advances practical applications based on synergistic chemical engineering, catalysis, and materials science research. Perspectives, challenges, and opportunities for trans-lational research towards commercial applications of methane cracking are discussed aiming at clean hydrogen production.

Plasma-catalytic CO2 hydrogenation is a complex chemical process combining plasma-assisted gas-phase and surface reactions. Herein, we investigated CO2 hydrogenation over Pd/ZnO and ZnO in a tubular dielectric barrier discharge (DBD) reactor at ambient pressure. Compared to the CO2 hydrogenation using Plasma Only or Plasma + ZnO, placing Pd/ZnO in the DBD almost doubled the conversion of CO2 (36.7%) and CO yield (35.5%). The reaction pathways in the plasma-enhanced catalytic hydrogenation of CO2 were investigated by in situ Fourier transform infrared (FTIR) spectroscopy using a novel integrated in situ DBD/FTIR gas cell reactor, combined with online mass spectrometry (MS) analysis, kinetic analysis, and emission spectroscopic measurements. In plasma CO2 hydrogenation over Pd/ZnO, the hydrogenation of adsorbed surface CO2 on Pd/ZnO is the dominant reaction route for the enhanced CO2 conversion, which can be ascribed to the generation of a ZnO x overlay as a result of the strong metal-support interactions (SMSI) at the Pd-ZnO interface and the presence of abundant H species at the surface of Pd/ZnO; however, this important surface reaction can be limited in the Plasma + ZnO system due to a lack of active H species present on the ZnO surface and the absence of the SMSI. Instead, CO2 splitting to CO, both in the plasma gas phase and on the surface of ZnO, is believed to make an important contribution to the conversion of CO2 in the Plasma + ZnO system.

Direct conversion of CH4 and CO2 to liquid fuels and chemicals under mild conditions is appealing for biogas conversion and utilization but challenging due to the inert nature of both gases. Herein, we report a promising plasma process for the catalyst-free single-step conversion of CH4 and CO2 into higher value oxygenates (i.e., methanol, acetic acid, ethanol, and acetone) at ambient pressure and room temperature using a water-cooled dielectric barrier discharge (DBD) reactor, with methanol being the main liquid product. The distribution of liquid products could be tailored by tuning the discharge power, reaction temperature and residence time. Lower discharge powers (10-15 W) and reaction temperatures (5-20 degrees C) were favourable for the production of liquid products, achieving the highest methanol selectivity of 43% at 5 degrees C and 15 W. A higher discharge power and reaction temperature, on the other hand, produced more gaseous products, particularly H2 (up to 26% selectivity) and CO (up to 33% selectivity). In addition, varying these process parameters (discharge power, reaction temperature and residence time) resulted in a simultaneous change in key discharge properties, such as mean electron energy (Ee), electron density (ne) and specific energy input (SEI), all of which are essential determiners of plasma chemical reactions. According to the results of artificial neural network (ANN) models, the relative importance of these process parameters and key discharge indicators on reaction performance follows the order: discharge power > reaction temperature > residence time, and SEI > ne > Ee, respectively. This work provides new insights into the contributions and tuning mechanism of multiple parameters for optimizing the reaction performance (e.g., liquid production) in the plasma gas conversion process.

Plasma-catalysis pyrolysis is a promising way to solve the problem of catalyst deactivation during plastic recycling. In this study, pyrolysis of polypropylene (PP) over zeolite ZSM-5 has been carried out in a two-stage fixed bed pyrolysis system with a coaxial dielectric barrier discharge (DBD) plasma reactor. The role of plasma on the pyrolysis process, as well as the stability of the plasma-catalytic system was investigated. Compared to conventional catalytic pyrolysis, plasma-catalysis pyrolysis increased gas products from 29 wt% to 47 wt% with 4.19 mmol/g H-2 formed, and improved the selectivity of BTX (benzene, toluene, xylene) whilst inhibiting the production of wax simultaneously. After 10 cycles, clear decreases in gas and oil yield (from 86 wt% to 48 wt%) and BTX selectivity (from 71 wt% to 39 wt%) were found in the conventional catalytic pyrolysis, however, nearly no variation was shown in the plasma-catalysis mode. The coupling of catalyst and plasma modified the catalysts acidic sites, while the radicals enhanced the pre-cracking of volatiles, resulting in less deposited coke. Overall, the introduction of plasma resulted in an obvious reduction in total costs and presented a feasible strategy for the recycling of waste plastic.

Industrial ammonia synthesis revolutionized global agriculture and industry, but it consumes significant amounts of energy and releases vast quantities of CO2. One alternative, electrocatalytic nitrogen reduction generally suffers from a low ammonia yield rate and poor selectivity. Here, a tandem "plasma-electrocatalysis" strategy was proposed to harvest ammonia from the air. An ammonia yield rate (similar to 1.43 mg(NH3 )cm(-2) h(-1)) with almost 100% faradaic efficiency was achieved during over 50 hours of stable operation at -0.33 V vs. RHE. The ammonia yield rate reached up to similar to 3.0 mg(NH3) cm(-2) h(-1) with a faradaic efficiency of similar to 62% at -0.63 V vs. RHE. This marked performance is achieved by separating activation of stable nitrogen molecules via non-thermal plasma, followed by selective ammonia synthesis via a cobalt single-atom electrocatalyst. This strategy may rival the Haber-Bosch process and the aspirational electrochemical nitrogen reduction at a distributed small-size ammonia production based on a techno-economic analysis.

In this work, a dielectric barrier discharge (DBD) plasma-enhanced NH3-selective catalytic reduction (NH3-SCR) of NOx over a Cu-Mn/SAPO-34 catalyst at low temperatures (<200 degrees C) and oxygen-rich conditions (14 vol.%) has been investigated using a two-stage post-plasma-catalytic (PPC) configuration. The results show a maximum NOx removal of 80 % and a 100 % N-2 selectivity without NH3 slip or the formation of by-products at a low specific energy input (SEI) of 32 J/L. Adding water vapor (5.7 vol.%) into the plasma NH3-SCR process does not negatively affect the removal of NOx, while the presence of C3H6 enhances the removal of NOx. In situ diffuse reflectance infrared spectroscopy (DRIFTS) combined with optical emission spectroscopic diagnostics has been employed to elucidate the reaction mechanism in the plasma-catalytic removal of NOx. We find that the formation of NO2 via NO oxidation in the first stage plasma gas-phase reaction enhances the Eley-Rideal (E-R) reaction on the surface of the Cu-Mn/SAPO-34 catalyst in the second stage catalytic NH3-SCR of NOx. The CuMn/SAPO-34 catalyst shows stable performance in the plasma-enhanced NH3-SCR of NOx after 5 cycles of catalyst regeneration. This work has successfully demonstrated a promising low-temperature plasma-catalytic solution for the effective NH3-SCR of NOx.

The effect of Al2O3 and BaTiO3 packing on the plasma-enhanced NOx synthesis from air was investigated in a packed-bed dielectric barrier discharge (DBD) reactor. The discharge characteristics are significantly influenced by packing different materials into the discharge gap. Compared with the DBD without packing, the presence of Al2O3 or BaTiO3 beads in the discharge effectively enhanced the charge accumulation, average electric field, and mean electron energy, all of which contribute to the enhanced production of NOx. The lowest energy consumption of 15.9 MJ mol−1 for NOx production was achieved when placing BaTiO3 beads in the DBD, which can be attributed to the increased mean electron energy using the BaTiO3 packing, facilitating the formation of more N2 excited species in the reaction. These results suggest that choosing proper packing materials can effectively reduce the energy cost for plasma NOx synthesis using DBD.

Direct conversion of methane into chemicals and fuels under mild conditions has been considered as a 'holy grail' of chemistry and catalysis in the 21st century. Plasma-catalytic partial oxidation of methane (POM) to higher-value liquid fuels and chemicals over supported transition metal catalysts (Ni/gamma-Al2O3, Cu/gamma-Al2O3 and Fe/gamma-Al2O3) has been investigated in a co-axial dielectric barrier discharge (DBD) reactor at room temperature and atmospheric pressure. The selectivity of oxygenates was 58.3% in the plasma POM reaction without a catalyst, while the combination of DBD with the catalysts enhanced the selectivity of oxygenates up to 71.5%. Of the three catalysts, Fe/gamma-Al2O3 showed the highest methanol selectivity of 36.0% and a significant methanol yield of 4.7%, while the use of Cu/gamma-Al2O3 improved the selectivity of C-2 oxygenates to 9.4%, which can be attributed to the presence of more acid sites on the surfaces of the Cu catalyst. The possible reaction pathways in the plasma-catalytic POM reaction have been explored by combined means of plasma electrical and optical diagnostics, analysis of gas and liquid products, as well as comprehensive catalyst characterization. The plausible reaction routes for the production of major oxygenate (methanol) on the Fe/gamma-Al2O3 surfaces have been proposed. The surface CHx species are found to be critical for methanol synthesis; they can be formed through the direct adsorption of CHx radicals generated in the plasma gas-phase reactions or through the dissociation of adsorbed CH4 on the catalyst surface.Y

In this study, plasma reforming of n-dodecane for the co-generation of COx-free hydrogen and C2 hydrocarbons at low temperature and ambient pressure has been investigated in a gliding arc discharge (GAD) reactor. The selective synthesis of H2, C2H2 and C2H4 and the energy efficiency for n-dodecane conversion can be tuned by changing different processing parameters including the gas flow rate, n-dodecane concentration and input voltage. The highest selectivities of H2 (76.7%), C2H2 (41.4%) and C2H4 (12.0%) were achieved with an n-dodecane conversion of 68.1%. The generation of mixed hydrogen, acetylene and ethylene offers the possibility for in-situ hydrogenation to enhance the selectivity of light olefins (e.g., ethylene) without prior gas separation. The plausible reaction mechanism and pathways in the plasma cracking of n-dodecane have been discussed through plasma emission spectroscopic diagnostics coupled with a comprehensive analysis of gas and liquid products. A strong correlation between the yield of C2 hydrocarbons and the relative intensity of C2 Swan bands was found, which suggests that C2 Swan bands could be used as a valuable probe to understand the generation of C2 hydrocarbons in the plasma reforming of hydrocarbon oils.

Abstract Several experiments on the study of the electron neutrino mass are based on high-statistics measurements of the energy spectrum following electron capture of the radionuclide 163Ho. They rely on the availability of large, radiochemically pure samples of 163Ho. Here, we describe the production, separation, characterization, and sample production within the Electron Capture in Holmium-163 (ECHo) project. 163Ho has been produced by thermal neutron activation of enriched, prepurified 162Er targets in the high flux reactor of the Institut Laue-Langevin, Grenoble, France, in irradiations lasting up to 54 days. Irradiated targets were chemically processed by means of extraction chromatography, which allowed separating the formed Ho from the 162Er target-material and from the main byproducts 170Tm and 171Tm, which are co-produced in GBq amounts. Decontamination factors of >500 for Er and of >105 for Tm and yields of 3.6·1016 and 1.2·1018 atoms of 163Ho were obtained, corresponding to a recovery yield of 95 % of Ho in the chemical separation. The Ho-fraction was characterized by means of γ-ray spectrometry, Inductively-Coupled-Plasma Mass Spectrometry (ICP-MS), Resonance Ionization Mass Spectrometry (RIMS) and Neutron Activation Analysis (NAA). In this process, the thermal neutron capture cross section of 163Ho was measured to σHo-163 to Ho-164m= (23±3) b and σHo-163 to Ho-164g= (156±9) b for the formation of the two isomers of 164Ho. Specific samples were produced for further purification by mass separation to isolate 163Ho from the Ho-isotope mixture, as needed for obtaining the energy spectrum within ECHo. The partial efficiency for this second separation step is (32±5) %.