Double Layer Capacitance Values Research Articles

Newly synthesized oxadiazole derivatives as corrosion inhibitors for mild steel in acidic medium: Experimental and theoretical approaches

Two new 2,5-disubstituted oxadiazole derivatives, namely, 2-benzyl-5-(4nitrophenyl)-1,3,4-oxadiazole (2B54NPO) and 2-(4-methoxyphenyl)-5-(phenoxymethyl)-1,3,4-oxadiazole (24MO5POO) were synthesized and used as corrosion inhibitors against deterioration in 1 M HCl aggressive media of mild steel by electrochemical impedance spectroscopy, weight loss measurement, PDP technique, and quantum chemical calculation. A scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDX) were used to perform morphological studies. The weight loss was measured at various dosages in the temperature range of 298–318 K during 12 h of immersion. As per weight loss analysis, 2B54NPO and 24MO5POO showed inhibition efficiencies of 96.54% and 92.19%, respectively at 300 ppm concentration. The EIS results reveal that increase in concentration of both 2B54NPO and 24MO5POO causes corresponding increase in the value of polarization resistance and decrease in the values of double layer capacitance. Potentiodynamic polarization studies suggest that both 2B54NPO and 24MO5POO behave as mixed-type corrosion inhibitors. In the EIS approach, the highest inhibition capability was determined to be 94.08% for 2B54NPO and 92.37 % for 24MO5POO at 300 ppm and 298 K. The adsorption mechanism of 2B54NPO and 24MO5POO on mild steel surface obeyed the Langmuir adsorption isotherm. PDP technique shows maximum inhibition efficiency values of 89.29% for 2B54NPO, and 88.85% for 24MO5POO respectively. The quantum chemical calculations provide the correlation between the inhibitor molecules and mild steel surface. SEM and EDX analyses were carried out to support the adsorption mode of corrosion inhibition.

Photoelectrocatalytic Oxidation of Methane Into Methanol Over BiVO4/AU/FeCo–LDH Catalysts

Conversion of methane into high value added chemicals and clean fuels such as methanol under mild conditions is of great importance to the chemical industry. However, traditional thermal catalytic of methane always suffer from harsh reaction conditions and poor product selectivity. Here, we reported photoelectrocatalytic oxidation of methane over BiVO4/Au/FeCo–LDH under simulated sunlight illumination with ambient‘ conditions. The results demonstrate that BiVO4/Au/FeCo–LDH exhibits excellent photoelectrochemical properties and catalytic activity. The double-layer capacitance ([Formula: see text]) value of BiVO4/Au/FeCo–LDH is estimated to be 3.00[Formula: see text]mF[Formula: see text]cm[Formula: see text], indicating its considerable electrochemical active areas. The photocurrent density of BiVO4/Au/FeCo–LDH reaches up to 1.46[Formula: see text]mA[Formula: see text]cm[Formula: see text] in methane atmosphere. The methanol yield for photoelectrocatalytic oxidation of methane is 8.46 times that of pure BiVO4, and the corresponding Faraday efficiency is 56.09%. Finally, the reaction mechanism of photoelectrocatalytic conversion of methane to methanol based on hydroxyl radical and methyl radical as intermediate products is proposed. Our finding is expected to provide new insight for the design of active and selective catalysts toward photoelectrocatalytic conversion of methane.

Electrodeposited laser – nanostructured electrodes for increased hydrogen production

In the present work, a novel approach has been employed to effectively enlarge the electrocatalytic area of the electrodes in an alkaline electrolysis setup. This approach consists of a two-step electrode fabrication process: In the first step, ultrashort laser pulses have been used to nanostructure the electrode surface. In the second step, electrodeposition of nickel particles was performed in a modified Watt's bath. The resulting electrodes have been found to exhibit a significantly increased hydrogen evolution reaction (HER) activity. Compared to the laser-nanostructured electrode (LN) and an untreated (i.e., flat) electrode, the electrodeposited-laser-nanostructured (ELN) electrode provides (i) enhanced electrochemical values (ii) a significant increase of double-layer capacitance (CDL) (values up to 1945 μF cm−2) compared to that of an LN electrode (288 μF cm−2) (iii) higher Jpeaks at CVs sweeps and (iv) lower Tafel slopes (−121 mV dec−1 compared to −157 mv dec−1). The ELN electrode provides an overpotential value of |η|100 = 264 mV, which shows a noteworthy 34% decrease compared to a flat Ni electrode and a 15% decrease to an (LN) electrode. Scanning electron microscopy (SEM) revealed that the electrodeposition of nickel on the LN nickel electrodes results in a dendrite-like morphology of the surface. Thus, the enhancement of the HER has been attributed to the dendrite-like geometry and the concomitant enlargement of the electrocatalytic area of the electrode, which presents an electrochemical active surface area (ECSA) = 97 cm−2 compared to 2.8 cm−2 of the flat electrode. The electrodes have also been tested in actual hydrogen production condition, and it was found that the ELN electrode produces 4.5 times more hydrogen gas than a flat Ni electrode and 20% more hydrogen gas than an LN electrode (i.e. without the extra nickel electrodeposition).

NIR Photothermal-Enhanced Electrocatalytic and Photoelectrocatalytic Hydrogen Evolution by Polyaniline/SnS2 Nanocomposites

A series of polyaniline (PANI)-decorated SnS2 nanoplates (PANI/SnS2) were produced via a hydrothermal method followed by a liquid–solid mixing. The PANI/SnS2 nanocomposites were composed of amorphous PANI and hexagonal-phase SnS2 nanoplates. Infrared thermal images revealed that PANI had an excellent near-infrared (NIR)-induced photothermal effect. Overall, the PANI/SnS2 nanocomposites showed better NIR-enhanced electrocatalytic and photoelectrocatalytic hydrogen evolution activity than bare SnS2 nanoplates. The optimized 4% PANI/SnS2 (which contained 4 wt % PANI) displayed the largest electrochemical double-layer capacitance (Cdl) value (0.85 mF cm–2) and the lowest Tafel slope of 66 mV dec–1 in 0.5 M H2SO4 under NIR irradiation. It was investigated and confirmed that the photothermal effect and the synergistic effects between SnS2 and PANI heterostructure played important roles in promoting electrocatalytic and photoelectrocatalytic hydrogen evolution processes.

Electrochemical behaviour of carbon steel in sodium chloride solution by using thiophenol derivative inhibitor

The corrosion inhibition performance of thiophenol has been evaluated for carbon steel immersed in sodium chloride solution by weight loss method. As a results of weight loss method, it gives the corrosion rate and inhibition efficiency. The increase of corrosion inhibition efficiency with increase in concentration of thiophenol derivative inhibitor. When increase in concentration of inhibitor, the corrosion rate decreases. It is because of the higher concentration of inhibitor solution which arrest the active site of a carbon steel by the way of forming protective layer on the surface of carbon steel. The mechanistic aspects of corrosion inhibition has been assessed by electrochemical studies such as potentio dynamic polarisation studies and AC impedance spectra. The decrease of corrosion current and double layer capacitance value, increase in linear polarisation resistance values and impedance values obtained from electrochemical studies suggest that the formation of protective layer on the carbon steel surface. Surface analysis of polished, corroded and inhibitor carbon steel surface has been evaluated by SEM.

Electrodeposition of Ni particles on laser nanostructured electrodes for enhanced hydrogen evolution reaction

In this study, a two-step electrode fabrication process is used to enlarge the electrocatalytic area of the electrodes and improve the hydrogen evolution reaction. Nickel electrodes were laser-nanostructured, and afterward, they were galvanostatically electrodeposited, a novel approach for electrodes used for HER. SEM and EDX analysis were performed. The electrochemical evaluation provided enhanced values of overpotential (η10 = 108 mV), Tafel slope (b = −121 mV dec−1) and double layer capacitance (1945 μF cm−2) compared to the literature. The stability of the electrodes was tested by its overpotential (|η100|=264 mV) in a current density of 100 mA cm−2.

Uticaj tiouree na otpornost na koroziju mekog čelika uronjenog u simulirani rastvor betonskih pora

The corrosion resistance of mild steel in simulated concrete pore solution (SCPS) in the absence and presence of thiourea has been investigated by polarization study and AC impedance spectra. Polarisation study reveals that thiourea system functions as anodic inhibitor. AC impedance spectra reveal that a protective film is formed on the metal surface. When mild steel is used as rebar, thiourea may be mixed with concrete. Thus the mild steel will be protected from corrosion. The protective film consists of iron-thiourea complex formed on metal surface. In the presence of thiourea the linear polarisation resistance increases, corrosion current decreases, charge transfer resistance (Rt) increases, impedance increases, phase angle increases and double layer capacitance (Cdl) value decreases. This formulation may find application in concrete technology.

Izračunavanje prave vrednosti kapaciteta dvojnog sloja iz konstantnog faznog elementa u impedansnim merenjima

Considering literature of electrochemical impedance spectroscopy (EIS) it was discovered that for calculation of the value of double-layer capacitance (Cdl) from the constant phase element (CPE) two equations, with or without solution resistance (Rs) could be used. After calculation of Cdl for defined values of CPE constant Ydl, CPE exponent , Rs and charge transfer resistance (Rct), it was confirmed in this work that different results for Cdl were obtained by including Rs in the calculation of Cdl. It was also stated that "it is quite difficult to understand how both parameters (Rct and Rs) could be expressed by the same time constant, i.e. the same parameter ." By investigating the hydrogen evolution reaction (HER) at Ni mesh 40 electrode in the solution of 1 M KOH at 25 oC using EIS measurements, it was shown that different Cdl vs. E plots were obtained using these two equations for Cdl calculation. A simple solution to avoid this problem with detailed explanation, the use of equation without Rs , has been suggested in this work.

Uticaj premaza na koroziju ploča trupa od mekog čelika u prirodnoj morskoj vodi

The corrosion resistance of mild steel (used to make hull plates in ship technology) in seawater before paint coating (Nippon paint, weatherbond advance) and after paint coating has been measured by electrochemical studies such as Polarisation study and AC impedance spectra. It is observed that after paint coating, the corrosion resistance of mild steel hull plates increases. Polarization study reveals that after paint coating, the linear polarization resistance increases and corrosion current decreases. AC impedance spectra reveal that in the presence of paint coating charge transfer resistance value increases, impedance value increases, phase angle increases and double layer capacitance value decreases.

High-Performance Supercapacitor Electrode Material Based on the Two-Dimensional/Three-Dimensional Architecture of MoS2–PbS Hybrid Material

The synthesis of the stable hybrid material for electrodes to exhibit stupendous supercapacitor functioning is an actual challenge. Here, we present a two-step synthesis by a chemical route method followed by a hydrothermal technique to produce two-dimensional (2D)/three-dimensional (3D) hybrid material, wherein MoS2 nanosheets were integrated with the 3D cube-like network of PbS. The multiple MoS2/PbS hybrid structures are synthesized by varying the concentration of PbS. The characterization tools, such as X-ray diffraction, Fourier transform infrared, and ultraviolet–visible spectroscopy, approve the co-existence of MoS2 and PbS, while field emission scanning electron microscopy and transmission electron microscopy conclusions approve the distinctive microstructures. Brunauer–Emmett–Teller is also performed to compare the surface areas of pristine MoS2 nanosheets and MoS2/PbS-based hybrid material. Remarkably, the optimized concentration of the metal sulfide (PbS)-loaded MoS2/PbS (MP100) hybrid structure yielded the highest double-layer capacitance value of 205.50 F/g in a 1 M Na2SO4 electrolyte (scan rate of 10 mV/s), whereas pure MoS2 nanosheets showed 40.04 F/g. The inclusion of metal sulfide heightened the supercapacitive parameters of pure MoS2 nanosheets. The significant supercapacitive application of the hybrid material can be accredited to the synergistic effect amid the 3D network of interconnected MoS2 nanosheets surrounded by metal sulfide (PbS) providing an enhanced surface area and the lowest charge transfer resistance.

Investigation of inhibitive performance of Betahistine dihydrochloride on mild steel in 1 M HCl solution

This study evaluated the corrosion retardation of mild steel with the use of Betahistine dihydrochloride drug as a sustainable inhibitor in HCl solution and various techniques like weight loss measurements, electrochemical analysis was used to understand the inhibition process. The thermodynamic and adsorption parameters were calculated and discussed on the inhibition behaviour. The corrosion inhibition (% IE) gave a sharp rise with the increased concentration of the Betahistine dihydrochloride drug and reduced efficiency was observed with increased temperature and increased immersion time. Approximately 96% corrosion inhibition efficiency was attained with optimized conditions of 1500 ppm of Betahistine dihydrochloride, 2 h, 1 M HCl at 298 K temperature. Inhibitor adsorption to mild steel abided by the Langmuir adsorption isotherm. Electrochemical impedance spectroscopy revealed the reduction in the value of constant phase element, dip in the values of double-layer capacitance and increase in the charge transfer resistance with increased concentration of Betahistine dihydrochloride drug. Furthermore, potentiodynamic polarization experiments substantiated the mixed type of behaviour. The techniques like scanning electron microscopy, atomic force microscopy, along with ultraviolet–visible spectroscopy, fourier transform infrared spectroscopy, were employed for surface morphology and theoretical models like quantum chemical and molecular dynamics simulations authenticated the experimental observation.

Protective effect of Toddalia asatica leaf extract on Mild steel in 1.0N HCl

A study has been made on the Novel corrosion inhibitor on mild steel in 1.0N HCl. Commonly deterioration of steel is caused due to various environmental and other chemical factors. It is unavoidable but protectable using inhibition methods. Here the usual inhibitor is replaced by green inhibitors to evade toxicity, easy availability, and to minimize the waste. This work seeks out to analyze the dried leaves of Todalia Asiatica as an inhibitor on mild steel in 1.0N HCl. The anticorrosive effectiveness of this inhibitor is studied by using non- electrochemical and electrochemical techniques. Non -electrochemical studies such as the effect of time (87.6%) and temperature (93.0%) at optimum concentration show the maximum inhibition efficiency of the inhibitor due to the formation of an inhibited layer by the inhibitor on the metal surface. Langmuir isotherm most closely fits into the info data obtained suggesting the physical adsorption between the extract and the mild steel substrate. Electrochemical such as potentiodynamic polarization studies proved that extract of Todalia Asiatica dried leaves is a cathodic type of inhibitor and 85.12% inhibition efficiency provided by the inhibitor. Charge Transfer Resistance (Rct) value increased and also Double-layer capacitance (Cdl) value decreases by EIS studies. The observed inhibitor efficiency at optimum inhibitor concentration is 84.05%. Surface and corrosion product Analysis (EDX/FTIR) was carried out to determine the corrosion-inhibitive properties of the samples.

Experimental and theoretical analysis of baclofen as a potential corrosion inhibitor for mild steel surface in HCl medium

The effect of Baclofen on the retardation of mild steel corrosion was examined by employing the weight loss, electrochemical techniques and theoretical calculations. Investigations depicted the increased inhibition efficiency with the increased amount of Baclofen as a corrosion inhibitor and maximum inhibition efficiency was obtained ∼97% at the concentration of 2000 ppm of Baclofen. Potentiodynamic polarization study showed that Baclofen as an inhibitor controlled both the anodic and cathodic reactions but with cathodic predominance. Electrochemical analysis showed a clear decrease in the values of double layer capacitance. Adsorption of Baclofen on the surface of mild steel followed Langmuir adsorption isotherm. Experimental results were validated with the help of quantum chemical, molecular dynamic simulation, and surface morphological study.

Origination of forced particle-void networks for superior electron and mass transfer in binder-free supercapacitors

Recent developments in the field of energy storage systems have led to the need for a process that can synthesize an electrode in a cost-effective and environmentally friend manner with excellent performance. In this study, we developed a noble electrode structure by direct powder deposition process of MnO2 powder for a pseudo-capacitor configuration. This homogeneous electrode has uniformly distributed pores and direct contact between MnO2 particles, which helps improve ionic transport in an aqueous electrolyte and electron transport between MnO2 particles. In addition, electrochemical impedance analysis confirms that the homogeneous MnO2 electrode structure by powder deposition has a considerably lower value of charge transfer resistance (∼ 100 times) and double layer capacitance (∼10 times) compared to those for paste-type electrodes. Furthermore, our electrodes maintain a high specific capacitance of 383.4 F g−1 at more than 2 mg cm−2 of mass loading, whereas the capacitance of the paste-type electrode decreases considerable.

Corrosion resistance and thermal stability of sputtered Fe44Al34Ti7N15 and Al61Ti11N28 thin films for prospective application in oil and gas industry

Fe-and Al-based thin-film metallic glass coatings (Fe44Al34Ti7N15 and Al61Ti11N28) were fabricated using magnetron co-sputtering technique, and their corrosion performances compared against wrought 316L stainless steel. The results of GI-XRD and XPS analyses demonstrated amorphous structure and oxide layer formation on the surface of the fabricated thin films, respectively. The potentiodynamic (PD) polarization test in chloride-thiosulfate (NH4Cl ​+ ​Na2S2O3) solution revealed lower corrosion current (Icorr) (0.42 ​± ​0.02 ​μA/cm2 and 0.086 ​± ​0.001 ​μA/cm2 Vs. 0.76 ​± ​0.05 ​μA/cm2), lower passivation current (Ipass) (1.45 ​± ​0.03 ​μA/cm2 and 1.83 ​± ​0.07 ​μA/cm2 Vs. 1.98 ​± ​0.04 ​μA/cm2), and approximately six-fold higher breakdown potential (Ebd) for Fe- and Al-based coatings than those of wrought 316L stainless steel. Electrochemical Impedance Spectroscopy (EIS) of both films showed 4- and 2-fold higher charge transfer resistance (Rct), 7- and 2.5-times higher film resistance (Rf), lower film capacitance values (Qf) (10 ​± ​2.4 ​μS-sacm-2, and 5.41 ​± ​0.8 ​μS-sacm-2 Vs. 18 ​± ​2.21 ​μS-sacm-2), and lower double-layer capacitance values (Qdl) (31.33 ​± ​4.74 ​μS-sacm-2, and 15.3 ​± ​0.48 ​μS-sacm-2 Vs. 43 ​± ​4.23 ​μS-sacm-2), indicating higher corrosion resistance of the thin films. Cyclic Voltammetry (CV) scan exhibited that the passive films formed on the Fe- and Al-based coatings were more stable and less prone to pitting corrosion than the wrought 316L stainless steel. The surface morphology of both films via SEM endorsed the CV scan results, showing better resistance to pitting corrosion. Furthermore, the thermal analysis via TGA and DSC revealed the excellent thermal stability of the thin films over a wide temperature range typically observed in oil-gas industries.

Enhancing electroanalytical performance of porous boron-doped diamond electrodes by increasing thickness for dopamine detection

Novel porous boron-doped diamond (BDDporous)-based materials have attracted lots of research interest due to their enhanced detection ability and biocompatibility, favouring them for use in neuroscience. This study reports on morphological, spectral, and electrochemical characterisation of three BDDporous electrodes of different thickness given by a number of deposited layers (2, 3 and 5). These were prepared using microwave plasma-enhanced chemical vapour deposition on SiO2 nanofiber-based scaffolds. Further, the effect of number of layers and poly-l-lysine coating, commonly employed in neuron cultivation experiments, on sensing properties of the neurotransmitter dopamine in a pH 7.4 phosphate buffer media was investigated. The boron doping level of ∼2 × 1021 atoms cm−3 and increased content of non-diamond (sp2) carbon in electrodes with more layers was evaluated by Raman spectroscopy. Cyclic voltammetric experiments revealed reduced working potential windows (from 2.4 V to 2.2 V), higher double-layer capacitance values (from 405 μF cm−2 to 1060 μF cm−2), enhanced rates of electron transfer kinetics and larger effective surface areas (from 5.04 mm2 to 7.72 mm2), when the number of porous layers increases. For dopamine, a significant boost in analytical performance was recognized with increasing number of layers using square-wave voltammetry: the highest sensitivity of 574.1 μA μmol−1 L was achieved on a BDDporous electrode with five layers and dropped to 35.9 μA μmol−1 L when the number of layers decreased to two. Consequently, the lowest detection limit of 0.20 μmol L−1 was obtained on a BDDporous electrode with five layers. Moreover, on porous electrodes, enhanced selectivity for dopamine detection in the presence of ascorbic acid and uric acid was demonstrated. The application of poly-l-lysine coating on porous electrode surface resulted in a decrease in dopamine peak currents by 17% and 60% for modification times of 1 h and 15 h, respectively. Hence, both examined parameters, the number of deposited porous layers and the presence of poly-l-lysine coating, were proved to considerably affect the characteristics and performance of BDDporous electrodes.

Carbon wrapped bimetallic NiCo nanospheres toward excellent HER and OER performance

The development of highly efficient and low-cost hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) dual-functional catalysts is one of the key issues in the energy conversion system of water splitting. In this work, the carbon wrapped bimetallic NiCo nanospheres were prepared via a simple annealing process. Furthermore, the effect of different molar ratio of Ni:Co on the electrocatalytic properties of the obtained samples were investigated. Among these obtained catalysts, sample (with the molar ratio of Ni:Co was 1:2) exhibited the best electrocatalytic performance both for HER and OER. Electrochemical analysis showed that the overpotentials were only 105 and 330 mV for HER and OER to reach a catalytic current density of 10 mA cm−2, respectively. The corresponding Cdl (electric double-layer capacitance) value can reach up to 17.1 mF cm−2. What is more, the I-t-tests were carried out to prove its superior long-term catalytic durability. It was demonstrated that the excellent properties of HER and OER can be attributed to the large Cdl of the sample, the optimized molar ratio of NiCo alloy as well as the improved stability and electron transfer efficiency via carbon coating. The schematic diagrams have been provided to better understand the possible formation process and electrocatalytic mechanism. In brief, this work could provide a feasible and simple route for the design of bimetallic-based electrode materials toward superior HER and OER performance.

Mo-incorporated three-dimensional hierarchical ternary nickel-cobalt-molybdenum layer double hydroxide for high-efficiency water splitting

Flowers-like 3D hierarchical ternary NiCoMo-layered double hydroxide (NiCoMo-LDH) spheres have been fabricated in substrate-free route via a one-pot hydrothermal method and utilized as efficient electrocatalysts for the OER and HER. The well-structured 3D hierarchical flowers were composed of numerous two-dimensional nanosheets, which inherently possess considerable electrochemical active sites, thereby enhancing catalytic activity. NiMo and CoMo binary LDHs, with similar morphology, were also prepared to illustrate the efficiency of the ternary LDH. The results indicate higher electrocatalytic activity for the ternary LDH as compared to binary LDHs under alkaline conditions. The NiCoMo-LDH required an overpotential as low as 202 and 93 mV to deliver a constant anodic and cathodic current density of 10 mA cm−2 for the OER and HER, respectively. Furthermore, the NiCoMo-LDH exhibited remarkable HER activity, affording a low overpotential of 198 mV at a current density of −100 mA cm−2. Moreover, it could offer a stable current density of 10 mA cm−2 for overall water splitting at 1.62 V in 1 M KOH with long-term stability for 20 h. The double-layer capacitance (Cdl) value indicated that the NiCoMo-LDH significantly influenced interface conductivity and the electrochemical active surface area. The ternary NiCoMo-LDH electrode yielded low Tafel slope values of 54 and 51 mVdec−1 for the OER and HER. Owing to the efficient incorporation of Ni, Co, and Mo in a layered structure, synergetic effect, and high electrochemical surface area, the NiCoMo-LDH exhibited remarkable electrocatalytic activity. Such eco-friendly ternary LDHs can be used in rechargeable metal–air batteries for industrial applications.

The Inhibition Mechanism of Surfactant Composite for Mild Steel Corrosion in NaCl Solution

The corrosion inhibition of sodium deodecylbenzenesulfonate (SDBS) surfactant and ZnSO4 on mild steel in 0.05 M NaCl solution was conducted through the impedance spectroscopy and linear polarisation measurement. The inhibitors performance was measured separately and as a mixed composite of both at a ratio of 200:200 ppm. Results obtained from both these measurements indicate high corrosion inhibition of the mild steel substrates was achieved. Porosity calculation of the formed inhibition layer was done through the obtained linear polarisation data, and its dielectric properties were deduced from the impedance measurements. Two possible structures of the formed inhibitive layers are proposed. The first structure involved the formation of a stable but porous zinc oxide/hydroxide layer with the surfactant filling up the pores, thus forming a continuous inhibitive barrier film layer while the second, involved a formation of a continuous inhibitive barrier layer due to the chelation of the surfactant and ZnSO4 compounds. The results obtained also indicated that corrosion resistance induced by the inhibitive barrier layers is much more dependent on its charge transfer resistance properties rather than its dielectric properties and that the corrosion inhibition provided is not directly related to the double-layer capacitance values of the barrier layer.

Proton Exchange Membrane Electrolyzer Emulator for Power Electronics Testing Applications

This article aims to develop a proton exchange membrane (PEM) electrolyzer emulator. This emulator is realized through an equivalent electrical scheme. It allows taking into consideration the dynamic operation of PEM electrolyzers, which is generally neglected in the literature. PEM electrolyzer dynamics are reproduced by the use of supercapacitors, due to the high value of the equivalent double-layer capacitance value. Steady-state and dynamics operations are investigated in this work. The design criteria are addressed. The PEM electrolyzer emulator is validated by using a 400-W commercial PEM electrolyzer. This emulator is conceived to test new DC-DC converters to supply the PEM ELs and their control as well, avoiding the risk to damage a real electrolyzer for experiment purposes. The proposed approach is valid both for a single cell and for the whole stack emulation.