Low Amount Of Carbon Research Articles

Does sustainable digital economy have implications for climate change? Novel evidence in the context of sustainable energy technologies

China has developed a wide variety of solutions to enhance environmental quality to address the challenges posed by climate change. In recent years, China has shifted more of its attention toward the digital economy to overhaul the structure of its economy. The digital economy is becoming increasingly essential, and its role in achieving sustainability is becoming gradually linked. The aims of sustainable development and the reduction of greenhouse gas emissions are being worked on using digital technologies. In the context of China, this research paper investigates the impact of digital economy on China's climate change from 1996 to 2017. The study comprehensively analyzes the carbon footprint of China's digital technologies, including data centers, e-commerce, and mobile devices. It identifies the key drivers of carbon emissions in China's digital economy and proposes practical strategies to reduce them. Using quantile regressions approach, this study finds that digital economy has a greater impact on CO2 emissions in provinces that already emit a relatively high amount of carbon and is diminished in provinces that already emit a relatively low amount of carbon. However, digital economy does not have any bearing on CO2 emissions for the first three quantiles (Q0.25, Q0.50 and Q0.75). This suggests that the effect of digital economy on CO2 emissions is only seen over the longer term. Therefore, it is important to build the digital structure in such a way as to optimize the structure of energy consumption. This can be accomplished by optimizing the structure. This allows for the possibility of the digital economy eventually achieving reduced levels of CO2 emissions.

Radiocarbon dating of microliter sized Hungarian Tokaj wine samples

Radiocarbon-based age determination of wine samples has a great tradition worldwide, but most of the applied techniques, such as liquid scintillation counting and gas proportional counting analyses, have had large sample size requirements. However, accelerator mass spectrometry (AMS) based radiocarbon dating methods require much lower amount of carbon. Up to now, only a few available studies applied the AMS method to the dating of wine. We tested a preparation and measurement protocol for wine radiocarbon dating, not only for the ethanol fraction but for the distillation residue and submilliliter level preparation method of the wine sample without separation was also applied, using capillaries of the twenty wine samples from the Hungarian Tokaj wine region. The reliability of our method was verified by a comparison of wine time series with the Northern Hemisphere Zone 1 atmospheric 14C data as a calibration curve. The measured 14C values of the two different fractions, the ethanol and distillation residue, and the milliliter-sized non-separated samples also were in good agreement with each other, which shows both fractions could be used for radiocarbon dating of wine samples. Small sample size (~10 μL) wine radiocarbon dating does not destroy a significant part of a bottle of wine.

Combined complementary imaging techniques in morphological analysis of Spongilla lacustris (Linnaeus 1759)

AbstractSponges, like Spongilla lacustris, as filter feeders, play an essential role in water purification in aquatic ecosystems. The body of this demosponge, in general, consists of both organic soft skeleton and a siliceous scaffold. Their construction of the spicule‐bundling scaffold as mechanical support for skeletal organic mesohyl seems crucial for filtration efficiency. Understanding the structure of the sponge's biosilica‐based scaffold as well as its location within three‐dimensional (3D) skeletal construct requires the introduction of effective analytical methods. The investigations focused on the morphology and architecture of skeletal elements of S. lacustris utilizing the combination of X‐ray computed microtomography (μCT) and scanning electron microscopy with energy‐dispersive X‐ray spectroscopy (SEM/EDS). The construction details, surface morphology and chemical composition of the sponge scaffold are presented. μCT provided the reconstructed 3D images of skeleton structures, including longitudinally and transversely oriented bundles of overlapping spicules, forming a ladder‐like construction as well as the length, geometric distribution, and the surface of the spicules. Further analyses based on SEM/EDS confirmed the proper identification of the structures and their localization and revealed a high abundance of silicon and a low amount of carbon and oxygen in spicules, high abundance of silicon, carbon and oxygen in layered membranes surrounding the bundles of spicules but predominating carbon in the pinacoderm. Combination of these techniques provides a unique image of the sponge body morphology. Verified set of tools may be used for further analyses of sponge body mechanics.

Characterizations of activated carbons and groundwater organic matter adsorption

Dissolved organic matter (DOM) is abundant in groundwater in Tunisia. In this study, the organic matter from groundwater was examined using elemental analysis, fluorescence and FTIR spectroscopies. In addition, total organic carbon (TOC), chemical oxygen demand (COD) and UV-absorbance at wavelength 254 nm (UV254) were measured. Elemental analysis indicated that groundwater contained a high amount of oxygen but a low amount of carbon. FTIR analyses revealed that polysaccharides were the main compounds present in the groundwater. The removal of DOM was studied by adsorbing activated carbon-supported aluminum. The characterization of DOM and activated carbon after adsorption confirms the removal of organic matter. The decrease in the BET surface of adsorbent after adsorption confirms that the pores are occupied by organic matter. TOC was removed by adsorption, and activated carbon-supported aluminum was superior (∼80%) to raw-activated carbon (∼52%), and may be explored to remove contaminants from wastewater.

Size-strain line-broadening analysis of anatase/brookite (TiO2)-based nanocomposites with carbon (C): XRPD and Raman spectroscopic analysis.

A size-strain line-broadening analysis of the XRPD patterns and Raman spectra for two anatase/brookite (TiO2)-based nanocomposites with carbon (C) was carried out and the results compared with those of a similar sample free of carbon. The crystal structures and microstructures of anatase and brookite, as well as their relative abundance ratio, have been refined from XRPD data by the Rietveld method (the low amount of carbon is neglected). The XRPD size-strain analysis resulted in reliable structure and microstructure results for both anatase and brookite. The experimental Raman spectra of all the samples in the region 100-200 cm-1 are dominated by a strong feature primarily composed of the most intense modes of anatase (Eg) and brookite (A1g). The anatase crystallite sizes of 14-17 nm, estimated by XRPD, suggest the application of the phonon confinement model (PCM) for the analysis of the anatase Eg mode, whereas the relatively large brookite crystallite size (27-29 nm) does not imply the use of the PCM for the brookite A1g mode. Superposition of the anatase Eg mode profile, calculated by the PCM, and the Lorentzian shape of the brookite A1g mode provide an appropriate simulation of the change in the dominant Raman feature in the spectra of TiO2-based nanocomposites with carbon. Raman spectra measured in the high-frequency range (1000-2000 cm-1) provide information on carbon in the investigated nanocomposite materials. The results from field-emission scanning electron microscope (SEM), thermogravimetric analysis (TGA), Fourier transform infrared (FTIR) spectroscopy and nitrogen physisorption measurements support the XRPD and Raman results.

Carbon Loss in Sediments and Sequestration in Vegetation after Wildfire and Mulching in a High-Severity Burned Area in NW Spain

ABSTRACT The effectiveness of mulching in reducing the risk of erosion has been evaluated in numerous studies. However, its effect on carbon loss has received less attention, despite the potentially negative effects on ecosystem recovery. In this study, the effects of straw helimulching on soil erosion and carbon loss in sediments were investigated after a severe wildfire in NW Spain during the first three years after fire. During the first year after the fire, the accumulated mean sediment yield was 12.4 Mg ha−1 in the control plots and 0.5 Mg ha−1 in the mulched plots. Soil erosion decreased sharply during the second year after the fire and was almost inexistent during the third year after the fire. No differences in carbon concentration were detected between treatments during the period of study. A significantly lower amount of carbon was lost after the mulching treatment due to its effectiveness in reducing sediment erosion. The mulching treatment did not significantly influence the amount of carbon sequestered in the vegetation. Although the application of mulch did not affect carbon fixation in vegetation, its application after fire can be considered a sustainable way of managing forest ecosystems to reduce the impact of fire on carbon emissions.

Biochar-mediated DNRA pathway of anammox bacteria under varying COD/N ratios

Coupling dissimilatory nitrate reduction to ammonium (DNRA) pathway with anammox process has a prominent advantage in enhancement of nitrogen removal. However, the anammox bacteria driven-DNRA is difficult to proceed at normal autotrophic circumstance. Herein, for the first time, biochar (prepared by bamboo) was used as a mediator to stimulate the DNRA pathway of anammox bacteria under varying chemical oxygen demand (COD) to nitrogen (COD/N) ratios (0.1–0.7), and the underlying stimulation mechanism was elucidated by metagenomics sequencing analysis. Results showed that biochar addition (10 g/L) stimulated DNRA pathway of anammox bacteria at low COD/N ratios (0.1–0.5), thus enhancing the nitrogen removal efficiency (NRE) of the anammox system by 7.2%–16.4% and 0.9%–3.0%, respectively, compared to that of tests without sodium acetate and biochar (p<0.05). This enhancement was attributed to the improved extracellular electron accepting capacity of anammox biomass by biochar. The easily obtained electrons (from sodium acetate) further increased the relative abundances of anammox-related (hzs) and complete DNRA-related (napAB and nrfAH) genes (p<0.05), which catalyze electron-consuming reactions. The stimulated anammox pathway and DNRA pathway further increased the specific anammox activity and the relative abundance of anammox bacteria (especially Ca. Jettenia) by 15.5%–23.0% and 11.3%–82.6% compared with that without biochar, respectively. Metagenomics sequencing also revealed that anammox bacteria, Ca. Jettenia caeni, was the main bacteria for DNRA metabolism in this system. Our findings reveal that biochar could selectively stimulate DNRA pathway of anammox bacteria affiliated by a low amount of carbon, which provides a novel strategy to improve the nitrogen removal of anammox-based processes.

The Role of City Forest: Study of Malang Urban Forest Contribution in Sequestrating Carbondioxide Emition

Malabar, as an urban forest has a potential in CO2 sequestration which was not documented yet. This quantitative descriptive research aimed to describe the contribution of Malabar urban forest in CO2 emission mitigation through calculating the amount of CO2 absorbed by the forest. The data collection used was non-destructive in which the indicators measured were DBH and the height of the trees with DBH more than 20 cm. The data gained then was analyzed using Alometric Chave formula to obtain the amount of plant biomass, carbon values, and CO2 values. The results showed that the potential of Malabar rban forest is not optimized yet as the low amount of carbon stored in this forest. Thus, it is suggested to enrich the trees planted with those which can sequestrate CO2 in much higher amount compare to the exist one.&#x0D; &#x0D; Kata kunci: CO2 sequestration, urban forest, Malabar urban forest

Stocks of Carbon in Logs and Timber Products from Forest Management in the Southwestern Amazon

Amazon forest management plans have a variety of effects on carbon emissions, both positive and negative. All of these effects need to be quantified to assess the role of this land use in climate change. Here, we contribute to this effort by evaluating the carbon stocks in logs and timber products from an area under forest management in the southeastern portion of Acre State, Brazil. One hundred and thirty-six trees of 12 species had DBH ranging from 50.9 cm to 149.9 cm. Basic wood density ranged from 0.3 cm−3 to 0.8 g cm−3 with an average of 0.6 g cm−3. The logs had a total volume of 925.2 m3, biomass of 564 Mg, and carbon stock of 484.2 MgC. The average volumetric yield coefficient (VYC) was 52.3% and the carbon yield coefficient (CYC) was 53.2% for logs of the 12 species. The sawn-wood products had a total volume of 484.2 m3, biomass of 302.6 Mg, and carbon stock of 149.9 MgC. Contributions of the different species to the total carbon stored in sawn-wood products ranged from 2.2% to 21.0%. Means and standard deviations for carbon transferred to sawn-wood products per-species from the 1252.8-ha harvested area ranged from 0.4 ± 1.1 MgC to 2.9 ± 0.4 MgC, with the largest percentages of the total carbon stored in wood products being from Dipteryx odorata (21.0%), Apuleia leiocarpa (18.7%), and Eschweilera grandiflora (11.7%). A total of 44,783 pieces of sawn lumber (such as rafters, planks, boards, battens, beams, and small beams) was obtained from logs derived from these trees. Lumber production was highest for boards (54.6% of volume, 47.4% of carbon) and lowest for small beams (1.9% of volume, 2.3% of carbon). The conversion factor for transforming log volume into carbon stored in sawn-wood products was 16.2%. Our results also show that species that retain low amounts of carbon should be allowed to remain in the forest, thereby avoiding low sawmill yield (and consequent generation of waste) and allowing these trees to continue fulfilling environmental functions.

Effect of heat and cryogenic treatment on wear and toughness of HSS AISI M2

Despite the promising results obtained with cryogenic treatment of tool steels, there are still contradictions regarding its benefits, and there is no consensus regarding its mechanisms in the steel microstructure. The goal of this work is to investigate the optimum heat treatment process parameters together with the cryogenic treatment. Samples of AISI M2 steel were austenitized at 1170, 1200 or 1230°C and quenched in salt bath. The cryogenic treatment was performed through nitrogen nebulization with a cooling/heating rate of 0.3°C/min, 24-h holding time at −190°C, before, after or between the double tempering. The influence of cryogenic treatment in AISI M2 steel was dependent on the previous austenitization temperature. No significant reduction in retained austenite was observed by deep cryogenic treatment. The benefits achieved in the resistance to abrasive wear and toughness are associated with lower amount of carbon in the martensite together with finer and more homogeneous carbide precipitation.

Changes in soil cadmium concentrations with time following cessation of phosphorus fertilizer inputs.

Cadmium (Cd) can accumulate in soil from the application of phosphorus fertilizer. However, there is little information on what happens to soil Cd concentrations when Cd inputs stop. This study used soil and pasture samples collected from a long-term field trial to measure changes in Cd concentrations in soil for 22 yr after Cd inputs from fertilizer had stopped and assessed whether the application of nitrogen (N) (50kg ha-1 yr-1 ) could increase plant uptake of Cd and reduce soil Cd concentrations. It was found that there was no significant change in total or labile soil Cd (1M CaCl2 extractable) concentrations after Cd inputs stopped. The application of N did not significantly (P<.05) increase dry matter yield or increase Cd solubility. As a result, N did not enhance plant uptake of Cd. A mass balance that included Cd loss via plant uptake and Cd leaching confirmed they were insufficient to result in a detectable decrease in soil Cd concentration over the 22-yr interval of the trial. It appears that even an acid soil with low amounts of carbon (2.67%), iron/aluminum oxides, and clay can still strongly retain Cd, preventing Cd depletion from the soil, despite stopping Cd inputs and trying to enhance plant uptake of Cd from the application of N fertilizer.

Enhanced critical current density at high magnetic fields in MgB2 with Ga/In acetylacetonate processed by spark plasma sintering

Dense samples (94–96%) with starting composition (MgB2)0.99(X-acac)0.01 (X-acac denotes Ga or In acetylacetonate) were obtained by spark plasma sintering. The resulting material is a superconducting composite, where carbon substitutes for boron in the crystal structure of MgB2. Added samples show enhanced critical current density at high magnetic fields and this is reflected in high values of irreversibility field (Hirr) at temperatures below 25 K when compared to a pristine sample. More efficient is In-acac addition and it promotes a Hirr of ∼12.4 T (100 A/cm2 criterion) at 5 K. Carbon substitution for boron in the crystal structure of MgB2 has a strong influence on the pinning force and its related parameters and promotes in the added samples a grain boundary pinning mechanism as the dominant one, whereas the pristine sample with a low amount of carbon shows a major mechanism of point pinning type. However, our analysis indicates on the synergetic effects of the carbon substituting for boron and of the microstructural details on pinning and critical current density. The result strongly emphasizes the significantly different behavior of the additive during processing of the MgB2 samples, although thermal analysis experiments on both additives show very similar decomposition patterns.

Deuterium inventory determination in beryllium and mixed beryllium-carbon layers doped with oxygen

Since the largest area of the JET first wall is composed of beryllium, it is expected that nuclear fuel is largely retained in beryllium-based co-deposits with low amounts of carbon. Co-deposited layers obtained in the laboratory, with similar stoichiometry with the ones found in JET ITER-like wall (ILW) experiments, can provide complementary information regarding the hydrogen isotopes inventory and release behaviour.We report on the analysis of the beryllium-based layers deposited by the direct current magnetron sputtering method on pure tungsten and silicon substrates. The thickness of studied layers with various amounts of deuterium, oxygen, and carbon was between 2 and 7 μm. Samples from the same batch were distributed to different laboratories and characterised by various analytical methods. Scanning electron microscopy was applied to determine the exact thickness, data from elastic backscattering spectrometry and nuclear reaction analysis to profile the depth content of light elemental species as deuterium, and thermal desorption spectroscopy to quantify the amount of deuterium and also to observe release kinetics.The main finding is that a high amount of deuterium, from 8 at.% up to 28 at.%, can be retained in the films. Deuterium release at a heating rate of 0.125 °C/s reached its maximum intensity at peaks of various widths and shape, which appeared at temperatures from 340 °C up to 660 °C, depending on the thickness, the layer stoichiometry and deposition parameters.

Dissolved organic matter extracted from groundwater and heavy metals behavior in Ain Senan-Kef, Tunisia

In this study, dissolved organic matter (DOM) extracted from Tunisian water was examined using elemental analysis, size exclusion chromatography, nuclear magnetic resonance spectroscopy, pyrolysis gas chromatography-mass spectrometry and fluorescence spectroscopy. DOM has been quantified with parameters including ultraviolet–visible, total organic carbon, chemical oxygen demand and specific UV-absorbance. Elemental analysis indicated that groundwater contained a high amount of oxygen but a low amount of carbon. Based on fluorescence indices, organic matter is dominated by biological/autochthonous species, which are typically observed in the waters. The use of GC/MS revealed the presence of proteins. The interactions of heavy metals (Hg, Zn and Cu) with DOM have been studied using X-ray diffraction, ICP-AES, Fluorescence and FTIR spectroscopies. Zn appears to be bound to humic acid primarily through carboxyl-functional groups, while Hg ions apparently are bound through carboxylic, phenolic and alcoholic moieties. Cu (II) is bound preferentially to oxygen and nitrogen containing functional groups. Organic matter was supposed to be organomineral complexes.

Process development and impact of intrinsic heat treatment on the mechanical performance of selective laser melted AISI 4140

The low alloy steel AISI 4140 (German grade 42CrMo4) is one of the most frequently used Quench & Tempering (Q&T) steels with a wide range of applicability. Until now, commercially available iron powders for additive manufacturing can be summed up by their low amount of carbon. Fusion welding of Q&T steels often leads to cracks due to brittle martensitic transformation and the associated volume change. Therefore, the selection of appropriate process parameters in laser powder bed fusion (LPBF) plays a key role for the final material properties and is achieved through utilization of a new process development strategy and evaluation of microstructural features of test cubes. In this work tensile specimens were successfully produced with optimal process parameters and mechanical tests of additively built samples indicate mechanical performance comparable with a 450 °C tempered state of conventionally cast material. By correlating the measured mechanical properties of LPBF samples to those of a conventional Q&T state, an estimation of the intrinsic heat treatment during LPBF was carried out using an inverse transient Hollomon–Jaffe approach. This analysis indicates that a rapid reheating rate of 103 − 105 °C/s to ≈700–800 °C of the previous built layers is the determinant for the low hardness found in the LPBF process of AISI 4140. This is also in accordance with the finely dispersed carbide precipitates in the as built condition. Furthermore, the effect of bed pre-heating on the final material tempering state was found to be negligible. This shows the importance of a balanced match between LPBF process parameters and subsequent application demands as well as necessary postprocessing steps.

Evaluation of a Catalyst Durability in Absence and Presence of Toluene Impurity: Case of the Material Co2Ni2Mg2Al2 Mixed Oxide Prepared by Hydrotalcite Route in Methane Dry Reforming to Produce Energy.

Ni, Co, Mg, and Al mixed-oxide solids, synthesized via the hydrotalcite route, were investigated in previous works toward the dry reforming of methane for hydrogen production. The oxide Co2Ni2Mg2Al2 calcined at 800 °C, Co2Ni2Mg2Al2800, showed the highest catalytic activity in the studied series, which was ascribable to an interaction between Ni and Co, which is optimal for this Co/Ni ratio. In the present study, Co2Ni2Mg2Al2800 was compared to a commercial catalyst widely used in the industry, Ni(50%)/Al2O3, and showed better activity despite its lower number of active sites, as well as lower amounts of carbon on its surface, i.e. less deactivation. In addition to this, Co2Ni2Mg2Al2800 showed stability for 20 h under stream during the dry reforming of methane. This good durability is attributed to a periodic cycle of carbon deposition and removal as well as to the strong interaction between Ni and Co, preventing the deactivation of the catalyst. The evaluation of the catalytic performances in the presence of toluene, which is an impurity that exists in biogas, is also a part of this work. In the presence of toluene, the catalytic activity of Co2Ni2Mg2Al2800 decreases, and higher carbon formation on the catalyst surface is detected. Toluene adsorption on catalytic sites, side reactions performed by toluene, and the competition between toluene and methane in the reaction with carbon dioxide are the main reasons for such results.

The effect of increasing Cu and Ni on a significant enhancement of mechanical properties of high strength low alloy, low carbon steels of HSLA-100 type

High strength low alloy steels (HSLAs) containing copper, nickel and low amount of Carbon are a new generation of high strength low alloy steels that are widely used in shipbuilding. Strengthening elements such as Cu, Ni, and to some extend C, play a significant role in this family of steels. By increasing the amount of Cu, Ni, and by selection of proper final temperature of rolling, austenitization and aging, it is possible to enhance the yield strength of this steel up to 160 ksi (1102 MPa) while at the same time toughness remains at an acceptable level. In this investigation, the effect of increasing Cu and Ni on mechanical properties of these steels was elaborated. Four steels with varying amounts of Cu and Ni were cast, and hot rolled by a thermomechanical controlled processing. The steels were then austenitized at 920 °C for 45 min followed by quenching in water. Finally, the steels were aged at 650 °C for one hour. Optical microscope, and Filed Emission Scanning Electron Microscope (FE-SEM) were used to study microstructural evolution. Mechanical properties variation was evaluated by tensile and microhardness tests. Results showed that by increasing the amount of these two elements, hardness and tensile strength were increased in thermomechanically controlled processed, austenitized and aged specimens. Yield strength values of the rolled samples were somehow scattered which was due to a slight difference in final rolling temperature and the subsequent rapid cooling. Yield strength under austenitization and quenching conditions increased by increasing the amount of Cu and Ni which could be due to the presence of Nb (C, N) precipitates. Increasing the amount of Cu precipitates after quench could also be another reason for yield strength increment. Increasing the amount of Cu and Ni in samples containing 4.16 and 7.65 wt% for each of these alloys led to the reduction of Ac1 (austenite formation temperature). Selecting aging temperature (650 °C) higher than the austenite formation temperature could probably lead to the growth of the carbides, softening of martensite layers and lower amount of dislocations density hence for the reduction of yield strength of the aged steels. As well, with the addition of the mentioned amounts of Cu and Ni, yield strength of 705 MPa (102.2 ksi), tensile strength of 1072 MPa (155.4 ksi), elongation of 14% and area reduction of 63% were obtained in the aged steels of this investigation.

Feasibility of Glow Discharge Nonthermal Plasma as an Alternative Pretreatment for Low-Carbon Wastewater in a Biological Nutrient Removal Plant

Abstract Biological treatment is insufficient for infield treatment of domestic wastewater that contains low amounts of carbon. This study proposes a pretreatment process for enhancing the nutrient...

Hydrogen production from ethanol: Synthesis of Ni catalysts assisted by chelating agents

The steam reforming of ethanol was studied over supported Ni catalysts. The catalysts were prepared by the wet impregnation method, using chelating solutions (ethylendiaminetetraacetic acid, EDTA; nitrilotriacetic acid, NTA; and citric acid, CA). The solids were characterised by means of X-ray diffraction, BET specific surface area, temperature programmed reduction, X-ray photoelectron spectroscopy and thermogravimetry analysis. The catalyst prepared from EDTA solution was the most active and selective, with a low amount of carbon deposited after 7 h in reaction. This behaviour was associated with an improvement in the Ni-CeO2 interaction induced by the small NiO particle size obtained from the use of a chelating agent. This sample also showed a high Ce3+/Ce4+ ratio and the smallest particle size of metallic nickel.

Nickel supported on YSZ: The effect of Ni particle size on the catalytic activity for CO2 methanation

The catalytic conversion of carbon dioxide to synthetic CH4 was studied on five Ni/YSZ samples, with the same nickel loading (10 wt%) but different Ni particle size. The catalysts, prepared by different methods, were characterized combining morphological (BET, TEM), structural (XRD, in-operando XAS), electronic (XPS, in-operando XANES) analysis and H2-TPR experiments. The results showed that catalytic activity and CH4 selectivity depended on size and morphology of Ni particles, and that type and amount of deposited carbon strongly depended on Ni0 morphology. The kinetic measurements revealed that both H2 and CO2 reactants were activated on Ni sites, and that YSZ support was not directly involved in the reaction mechanism.The most efficient catalyst was that prepared by wet impregnation with Ni(EDTA)2− complex due to the high Ni0 dispersion.This catalyst showed low amount of carbon and remarkable stability over time on stream. In-operando XAS showed that it did not undergo deactivation by Ni0 → Ni2+ oxidation using high CO2 concentration, thus it is applicable in dynamic conditions like those typical in the energy storage from renewable sources process.