Hydrogen Gas Generation Research Articles

Electrodeposition with intermittent addition of trimethylamine borane to produce ductile bulk nanocrystalline Ni–B alloys

We developed a technique to dope electrodeposited Ni with B to produce ductile bulk electrodeposits of Ni–B alloys. The conventional method, in which TMAB is added as a source for B-doping to the deposition bath before electrodeposition, affected only the first layer, producing two layers of Ni–B alloys and pure Ni in the bulk electrodeposits. These inhomogeneous specimens showed poor tensile properties, because of processing-defects presented in the layer of Ni–B alloys. These defects were produced because TMAB immediately decomposes during electrodeposition, generating hydrogen gas. In contrast, the developed technique for B-doping, in which TMAB is added intermittently during electrodeposition, produced a more-uniform B content of 0.04 at.% in the growth direction. This B distribution resulted in a uniform nanocrystalline structure with a grain size of ~28 nm. The sample of bulk nanocrystalline Ni–B alloys exhibited a good tensile elongation of 7.6% with a high tensile strength of 1.45 GPa. The developed B-doping technique avoids the harmful effects of the hydrolysis of boron compounds, and it can produce electrodeposited bulk nanocrystalline Ni–B alloys with good ductility.

EVALUATING THE CRUCIAL FACTORS AFFECTING HYDROGEN GAS GENERATION FROM MUNICIPAL SOLID WASTE INCINERATION BOTTOM ASH (MSWIBA)

In this study, we examined the factors influencing hydrogen gas generation from municipal solid waste incineration bottom ash and methods to improve this process. A series of mixing and stirring experiments using bottom ash and water were conducted. The reaction temperature, liquid-solid ratio, stirring rate, and presence or absence of a grinding treatment were set as the experimental parameters. According to the results obtained in the present study, the optimum temperature for efficient recovery of hydrogen gas was 50°C. When the liquid-solid ratio was 5, or exceeded 3, more hydrogen gas was generated. When the stirring rate was 600 rpm, or exceeded 400 rpm, more hydrogen gas was produced. When bottom ash was crushed, the initial gradient of hydrogen gas generation dramatically increased.

Hydrogen gas generation using a metal-free fluorinated porphyrin

Free-base meso-tetra(pentafluorophenyl)porphyrin, 1, is electrocatalytically active for hydrogen gas generation in the presence of p-toluenesulfonic acid. The electrochemical potential of hydrogen evolution (-1.31 V vs. Fc/Fc+ in THF) is comparable to those of metal containing electrocatalysts such as metallated porphyrins or other metallated macrocycles. Combining experimental observations and DFT computations, we propose the most favorable hydrogen generation mechanism to be a (1) reduction, (2) protonation, (3) reduction, (4) protonation (E-P-E-P) pathway.

Understanding the Dynamics of Primary Zn-MnO2 Alkaline Battery Gassing with Operando Visualization and Pressure Cells

The leading cause for safety vent rupture in alkaline batteries is the intrinsic instability of Zn in the highly alkaline reacting environment. Zn and aqueous KOH react in a parasitic process to generate hydrogen gas, which can rupture the seal and vent the hydrogen along with small amounts of electrolyte, and thus, damage consumer devices. Abusive conditions, particularly deep discharge, are known to accelerate this “gassing” phenomena. In order to understand the fundamental drivers and mechanisms for such gassing behavior, the results from multiphysics modeling, ex-situ microscopy and operando measurements of cell potential, pressure and visualization have been combined. Operando measurements were enabled by the development a new research platform that enables a cross-sectional view of a cylindrical Zn-MnO2 primary alkaline battery throughout its discharge and recovery. A second version of this cell can actively measure the in-cell pressure during the discharge. It is shown that steep concentration gradients emerge during the cell discharge through a redox electrolyte mechanism, leading to the formation of high surface area Zn deposits that experience rapid corrosion when the cell rests to its open circuit voltage. Such corrosion is paired with the release of hydrogen and high cell pressure – eventually leading to cell rupture.

A facile non-photocatalytic technique for hydrogen gas production by hydroelectric cell

Hydrogen gas is a zero-emission fuel for clean environment. In present work a novel environment friendly hydrogen producing technique based on nascently invented Hydroelectric cell has been reported. Hydroelectric cell is one of the unique non-polluting H2 gas generation methods compared to photo-biosynthesis, photo-electro-catalysis and thermo-chemical etc. Spontaneous dissociation of water molecule by Hydroelectric cell (HEC) has led this study for effective production of hydrogen gas. Moreover, a nanoporous lithium substituted magnesium ferrite used in HEC dissociates water molecule to produce hydrogen without using any electrolyte and light. Ferrite pellet combined with zinc and silver electrodes known as hydroelectric cell produces zinc hydroxide and hydrogen gas as a result of redox reaction. Nanoporous and oxygen deficient ferrite pellet has been synthesised with optimized processing conditions. Maximum average nanopore size distribution has been obtained 3.8 nm by N2 adsorption-desorption isotherm. Surface dangling bonds of unsaturated cations and oxygen vacancies in ferrite chemidissociate water molecule into hydroxide and hydronium ion. High purity hydrogen gas is produced continuously by applying different external voltage only on hydroelectric cell. Collected gas has been analysed by gas chromatography in comparison to pure reference hydrogen gas. This technique has produced hydrogen in large quantity 1.856 mmol/h compared to existing photocatalytic active ferrite methods. Hydrogen gas generation by HEC is an exclusively facile, low cost and novel technique.

密閉式冷温水配管からの水素ガス生成に関する研究 （第２報）水素ガス発生評価と発生抑制の検討

密閉式冷温水配管からの水素ガス生成に関する研究 （第２報）水素ガス発生評価と発生抑制の検討

Hydrogen generation due to water splitting on Si - terminated 4H-Sic(0001) surfaces

The chemical reactions of hydrogen gas generation via water splitting on Si-terminated 4H-SiC surfaces with or without C/Si vacancies were studied by using first-principles. We studied the reaction mechanisms of hydrogen generation on the 4H-SiC(0001) surface. Our calculations demonstrate that there are major rearrangements in surface when H2O approaches the SiC(0001) surface. The first H splitting from water can occur with ground-state electronic structures. The second H splitting involves an energy barrier of 0.65 eV. However, the energy barrier for two H atoms desorbing from the Si-face and forming H2 gas is 3.04 eV. In addition, it is found that C and Si vacancies can form easier in SiC(0001)surfaces than in SiC bulk and nanoribbons. The C/Si vacancies introduced can enhance photocatalytic activities. It is easier to split OH on SiC(0001) surface with vacancies compared to the case of clean SiC surface. H2 can form on the 4H-SiC(0001) surface with C and Si vacancies if the energy barriers of 1.02 and 2.28 eV are surmounted, respectively. Therefore, SiC(0001) surface with C vacancy has potential applications in photocatalytic water-splitting.

Direct Synthesis of Amides by Dehydrogenative Coupling of Amines with either Alcohols or Esters: Manganese Pincer Complex as Catalyst.

The first example of base-metal-catalysed synthesis of amides from the coupling of primary amines with either alcohols or esters is reported. The reactions are catalysed by a new manganese pincer complex and generate hydrogen gas as the sole byproduct, thus making the overall process atom-economical and sustainable.

Direct Synthesis of Amides by Dehydrogenative Coupling of Amines with either Alcohols or Esters: Manganese Pincer Complex as Catalyst

AbstractThe first example of base‐metal‐catalysed synthesis of amides from the coupling of primary amines with either alcohols or esters is reported. The reactions are catalysed by a new manganese pincer complex and generate hydrogen gas as the sole byproduct, thus making the overall process atom‐economical and sustainable.

Cutting of hard and brittle insulating materials using spark discharge-assisted diamond wire sawing

Hard and brittle insulating materials have good application prospects but are difficult to machine. This research focuses on the feasibility of cutting such materials using spark discharge-assisted diamond wire sawing. By the electrochemical discharge machining (ECDM) method, spark discharges are generated on the diamond wire. However, no spark discharge is produced when the thickness of workpiece is beyond 5.0mm, because of the difficulty in generating hydrogen gas film to electrically insulate the diamond wire from the electrolyte. To solve this problem, an oil film is online coated on the diamond wire to separate it from the electrolyte. Oil film may be absent at some micro areas where electrochemical reaction occurs and hydrogen gas is generated. Consequently, an electrically insulating film, which consists of oil and hydrogen gas, is formed on the diamond wire. Experimental results show that evenly distributed spark discharges are generated during the cutting of a 36.0mm thick workpiece. The combination of spark discharge and diamond wire sawing facilitates the spalling of hard and brittle insulating materials. The material removal rate (MRR) and surface roughness increase with the DC voltage, wire speed, and counterweight mass.

Two-dimensional metal phosphorus trisulfide nanosheet with solar hydrogen-evolving activity

The development and utilization of photocatalysts to realize water-splitting without any external bias or sacrificial agents has received the limelight. As a novel two-dimensional layered material, metal phosphorus trichalcogenides (MPTs) cause wide research interest, presently. However, the growth of ultrathin two-dimensional MPT crystals is a great challenge to hinder their application. Here, we initially grow few-atomic layered nickel phosphorus trisulfide (NiPS3) as promising photocatalyst for hydrogen evolution. The as-prepared NiPS3 hexagonal nanosheet, as thin as few atomic layers (≤ 3.5nm), has lateral size of larger than 15µm. These ultrathin NiPS3 crystals can directly generate hydrogen gas from pure water without any sacrificial agents under sunlight. With ultraviolet photoelectron spectrometer and electrochemical impedance spectroscopy, we show that the attractive photocatalytic activity of the ultrathin NiPS3 crystals arise from their appropriate positions of the band edges. This discovery is expected to make a contribution to develop next generation solar-fuel conversion catalysts for H2 production.

Gold Aerogel As a Novel Catalyst for Hydrogen Generation Reaction from a Hydrogen Feedstock Material

With the limited supply of fossil fuels becoming more of a concern, there has been an increased focus in finding alternative sources of energy. One source of clean energy is hydrogen gas. Studies have been done examining the generation of hydrogen gas from water, which is an energy intensive process. There has been less effort in generating hydrogen gas from a solid feedstock, such as sodium borohydride. In the presence of water, sodium borohydride releases hydrogen gas slowly. In order to be used as an efficient source of energy, this reaction needs to be catalyzed so the reaction happens at a sufficient rate. One area of catalysis is the noble metals such as gold at the nanoscale. Using metal nanoparticles is a cost-effective way to use these metals as a catalyst, because much less of the bulk precursor is needed. Without a support, the nanoparticles will not be as effective, so aerogels of gold nanoparticles were synthesized and tested to determine its effectiveness as a catalyst [1]. The evolution of hydrogen was measured using a previously described water displacement system [2,3]. The data show an increase in the efficiency of the generation of hydrogen gas with the addition of gold aerogels when compared to the un-catalyzed reaction. The gold aerogel catalyzed reaction has a rate constant of 15.8 L mol-1 hr-1, compared to the un-catalyzed reaction which produced hydrogen at rate of 6.42 L mol-1 hr-1, and was determined to be a second order reaction. This catalyzed process produced 92% more moles of hydrogen gas than the un-catalyzed reaction in the same time period. References D. Wen, W. Liu, D. Haubold, C. Zhu, M. Oschatz, M. Holzschuh, A. Wolf, F. Simon, S. Kaskel, and A. Eychmüller, ACS Nano, 2559–2567, Feb. 2016.T. Dushatinski, C. Huff, and T. Abdel-Fattah, Applied Surface Science, 385, 282 (2016).C. Huff, T. Dushatinski, A. Barzanji, N. Abdel-Fattah, K. Barzanji, and T. Abdel-Fattah, ECS J Solid State, 6, M69-M71 (2017).

A Ni-Al Thin Film Electrocatalyst for the Reduction of CO2 to Multi-Carbon Oxygenated Organics

The amount of CO2 in the atmosphere has increased dramatically since industrialized processes (e.g., manufacturing, agriculture) became commonplace. Current concentrations of this greenhouse gas exceed 400 ppm, far surpassing the pre-Industrial Revolution value of 280 ppm,1 and it is unlikely that the worldwide average will dip below this massive value. The many environmental, human health, and societal challenges associated with elevated CO2 levels, coupled with an impending fossil fuel shortage, have inspired a search for electrocatalysts that transform CO2 into useful products, such as chemical feedstocks or fuels. While several classes of CO2-reducing electrocatalysts exist (e.g., molecular catalysts, framework complexes, nanoparticles), practical advantages favor the use of heterogeneous catalyst varieties. Single-metal electrodes have been well-characterized for their reactivity toward aqueous CO2, but the majority favor the generation of hydrogen gas from protons in solution as opposed to CO2 reduction. Of the handful of single-metal electrodes capable of reducing CO2, only copper has been shown to generate multiple-carbon products from the single-carbon starting material.2–4 Even so, copper electrodes have suffered from selectivity and stability challenges,5 and much effort is now being focused on achieving highly reduced products that address these practical problems. Metal alloys constitute a relatively understudied class of heterogeneous CO2 reduction catalysts, despite the fact that their abilities to transform CO2 often contrast greatly with the CO2 reduction capacity of their component metals. Most alloy catalysts studied generate either CO or HCOOH, and a handful can generate two-carbon products from CO2.6–10 Inspired by a desire to expand the scope of bimetallic alloy CO2 reduction catalysts, we have shown that nickel-aluminum thin films electrochemically reduce CO2 to an array of oxygenated organic species containing one to three carbon atoms. The electrochemical transformation is performed in aqueous solution at –1.38 V vs. Ag/AgCl with good stability over time. This species is the first non-copper-containing electrocatalyst capable of generating three-carbon products from CO2, thereby addressing many selectivity and stability challenges posed by copper-based electrodes. We will describe the synthesis and materials characterization of nickel-aluminum alloy catalysts, including powder X-ray diffraction, energy-dispersive X-ray spectroscopy, and scanning electron microscopy. The material’s behavior toward CO2 reduction will be presented as determined using cyclic voltammetric analysis, bulk electrolysis, and electrochemical condition optimization. 1H-NMR, 13C-NMR, 2D-NMR, and mass spectrometry experiments are used to confirm the assertion that all multiple-carbon products are derived entirely from CO2 starting material, and mechanistic insights will be presented. This information will be used to suggest design principles for the further study of bimetallic species as heterogeneous CO2 reduction catalysts, and our ongoing work in this area will be summarized.

Properties of Lightweight Composites Using Industry Wastes with NaOH Alkaline Activator

Lightweight concrete has been adopted to prefabricated elements such as facades, staircases and wall systems in housing projects. Many research have been carried out on production of lightweight panels without using ordinary portland cement. The objective of this experimental study was to develop construction materials applicable to lightweight wall system by using ground granulated blast furnace slag and paper ash, which are industrial by-products. Specifically, we carried out an experimental research on the properties of a lightweight matrix that could have application to lightweight wall systems without involving any use of Portland cement that emits massive amount of carbon dioxide (CO2) from chemical process and burning fuel; the major culprit behind global warming. In this study, we used NaOH alkaline activator to achieve the strength of a ground granulated blast furnace slag-based matrix without using general Portland cement. As a result, the mechanism was uncovered as to how NaOH alkaline activator led to the generation of hydrogen gas through reaction with the unreacted Si of paper ash. In addition, we found that construction materials applicable to lightweight wall systems could be manufactured by using ground granulated blast furnace slag and paper ash, industrial by-products.

Electrocatalytic hydrogen gas generation by cobalt molybdenum disulfide (CoMoS2) synthesized using alkyl-containing thiomolybdate precursors

Cobalt molybdenum disulfide, (CoMoS2) catalysts are evaluated as active electrocatalysts for the production of hydrogen gas in acidic aqueous media. These highly-active hydrogen evolution reaction (HER) catalysts are obtained from pretreatment of ammonium tetrathiomolybdate (ATM) with different amines precursors, and characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM) and their surface areas are determined by Brunauer–Emmett–Teller (BET) surface area analyses. Electrochemical studies indicate that these CoMoS2 materials exhibit enhanced catalytic performance for hydrogen gas production with overpotentials ranging from 0.127 to 0.144 V, which are significant less than CoMoS2 synthesized directly from ATM under the same synthetic techniques (0.173 V). These CoMoS2 catalysts are also stable in the presence of strong acidic media after a considerably long period of time (10 h) for maintaining their efficiencies for hydrogen gas evolution.

High-Efficiency Water-Splitting Solar Cells with Low Diffusion Resistance Corresponding to Halochromic Pigments Interfacing with ZrO2

ZrO2 nanoparticle films coated with halochromic pigments are applied to water-splitting solar cells. On the basis of our results, ZrO2 nanoparticle films coated with methyl orange have remarkable water-splitting properties. Under positive applied voltages and AM 1.5G irradiation, the highest hydrogen gas generation rate (1.8 mL/h·cm2) is measured for ZrO2 nanoparticle films coated with methyl orange in 0.2 M H2SO4 water solution as electrolyte. As the electrolyte is changed from KHCO3 water solution to the H2SO4 water solution, the interface resistance between ZrO2 corresponding to halochromic pigments is reduced (from 107 to 11.7 Ω·m) and the electron diffusion coefficient is raised (821.67%).

Alkali-thermal gasification and hydrogen generation potential of biomass

Generating hydrogen gas from biomass is one approach to lowering dependencies on fossil fuels for energy and chemical feedstock, as well as reducing greenhouse gas emissions. Using both equilibrium simulations and batch experiments with NaOH as a model alkaline, this study established the technical feasibility of converting various biomasses (e.g., glucose, cellulose, xylan and lignin) into H2-rich gas via catalyst-free, alkalithermal gasification at moderate temperatures (as low as 300 °C). This process could produce more H2 with less carbon-containing gases in the product than other comparable methods. It was shown that alkali-thermal gasification follows C x H y O z + 2xNaOH + (x–z)H2O = (2x + y/2–z)H2 + xNa2CO3, with carbonate being the solid product which is different from the one suggested in the literature. Moreover, the concept of hydrogen generation potential (H2-GP)—the maximum amount of H2 that a biomass can yield, was introduced. For a given biomass C x H y O z , the H2-GP would be (2x + y/2–z) moles of H2. It was demonstrated experimentally that the H2-GP was achievable by adjusting the amounts of H2O and NaOH, temperature and pressure.

Analysis of hydrogen and dust explosion after vacuum vessel rupture: Preliminary safety analysis of Korean fusion demonstration reactor using MELCOR

Hydrogen explosion is one of the most dangerous accident phenomena in both nuclear fusion and fission reactor. In the typical fusion reactor, tritium and deuterium are fuel elements for fusion reaction, and they exist in condensed state around the cryo-pump in the normal operation condition. In the accident situation, increasing heat transfer system temperature can mobilize lots of tritium in the vacuum vessel. And then, coolant can react with high-temperature structures generating hydrogen gas inside vacuum vessel. In addition, air ingress into plasma terminates fusion reaction producing activated dust on the first wall plasma facing surfaces. Through these series of process, mobilized tritium and dust aerosol can explode in the vacuum vessel and damage the containment building integrity, making a sort of source term leakage to environment through various system volumes. In this paper, preliminary safety analysis for hydrogen and dust explosion accident for assumed design of Korean fusion demonstration reactor is conducted. An MELCOR system analysis code is used to simulate this accident and parametric analysis to investigate effect on the accident scale and safety systems like detritiation system such as heating, ventilation, and air conditioning isolation system and pressure suppression system. As a result, aerosol distribution of each control volume and its release route are estimated, and final aerosol release to the environment is compared with release guideline for ITER. The amount of mobilized aerosol in demonstration reactor is evaluated conservatively using ITER normal operation condition.

Hydrolytic reaction of waste aluminum foils for high efficiency of hydrogen generation

Hydrolyzed waste aluminum foil in low alkaline aqueous solution and concomitant additives are evaluated to generate hydrogen gas. The result of hydrogen generation using wasted Al foil is efficient in comparison with traditional Al powder. A polythene film coated on waste Al foil was removed by immersing into nitric acid for 5 h prior to hydrolyzed reaction. Low alkaline solution (0.75 M NaOH) combined with Bi additives at elevating temperature (70 °C) in waste Al foil-water hydrolysis system enable to increase hydrogen generation rate to 30 ml s−1 g−1 and total volume 1300 ml g−1. The optimized result is attributed to the micro-galvanic cell formation between Al/Bi and removing hydroxide on Al foil surface by alkaline solution. In this report we develop low cost and waste recovery by hydrolyzing waste Al foil. High efficiency of hydrogen generation is achieved by low alkaline concentration and reducing activation energy. Al oxidation mechanism is explained by the linear-parabolic growth model and polarization curves indicate that corrosion potential of Al foils did not abruptly degrade and the corrosion capability with reliability were verified.

Modeling and Analysis of Solar Photovoltaic Assisted Electrolyzer-Polymer Electrolyte Membrane Fuel Cell For Running a Hospital in Remote Area in Kolkata, India

The present work consists of the modeling and analysis of solar photovoltaic panels integrated with electrolyzer bank and Polymer Electrolyte Membrane (PEM) fuel cell stacks for running different appliances of a hospital located in Kolkata for different climatic conditions. Electric power is generated by an array of solar photovoltaic modules. Excess energy after meeting the requirements of the hospital during peak sunshine hours is supplied to an electrolyzer bank to generate hydrogen gas, which is consumed by the PEM fuel cell stack to support the power requirement during the energy deficit hours. The study reveals that 875 solar photovoltaic modules in parallel each having 2 modules in series of Central Electronics Limited Make PM 150 with a 178.537 kW electrolyzer and 27 PEM fuel cell stacks, each of 382.372 W, can support the energy requirement of a 200 lights (100 W each), 4 pumps (2 kW each), 120 fans(65 W each) and 5 refrigerators (2 kW each)system operated for 16 hours, 2 hours,15 hours and 24 hours respectively. 123 solar photovoltaic modules in parallel each having 2 modules in series of Central Electronics Limited Make PM 150 is needed to run the gas compressor for storing hydrogen in the cylinder during sunshine hours. Article History: Received Feb 5th 2017; Received in revised form June 2nd 2017; Accepted June 28th 2017; Available onlineHow to Cite This Article: Talukdar, K. (2017). Modeling and Analysis of Solar Photovoltaic Assisted Electrolyzer-Polymer Electrolyte Membrane Fuel Cell For Running a Hospital in Remote Area in Kolkata,India. International Journal of Renewable Energy Development, 6(2), 181-191.https://dx.doi.org/10.14710/ijred.6.2.181-191