共查询到20条相似文献,搜索用时 31 毫秒
1.
Dragica Lj. Stojić Tomislav D. Grozdić Milica P. Marčeta Kaninski Aleksandar D. Maksić Nataša D. Simić 《International Journal of Hydrogen Energy》2006
Intermetallics phases along Mo–Pt phase diagram have been investigated as cathode materials for the production of hydrogen by electrolysis from water KOH solutions, in an attempt to increase the electrolytic process efficiency. These materials were compared with conventional cathodes (Fe and Ni), often used in the alkaline electrolysis, and also with the intermetallic Ti–Pt. An significant upgrade of the electrolytic efficiency using intermetallics in pure KOH electrolyte was achieved in comparison with conventional cathode materials. 相似文献
2.
《Journal of power sources》2005,145(2):278-281
With the idea to improve the efficiency of the electrolytic production of hydrogen by electrolysis, from water KOH solutions, the intermetallic Hf2Co was investigated as cathode. This cathode was used single or in combination with ionic activators, and compared with several intermetallics previously investigated: Hf2Fe, TiPt, and PtMo3. A comparison with conventional cathode, nickel, was also evaluated. An significant upgrade of the electrolytic efficiency using intermetallics was achieved in comparison with conventional cathode materials. The influence of ionic activators on the process efficiency was significant, too.The effects of those cathode materials on the electrolytic evolution of hydrogen were discussed in the context of transition metals features that issue from their electronic configuration. 相似文献
3.
Dragica Lj. Stojić Tomislav D. Grozdić Milica P. Marčeta Kaninski Vojislav Đ. Stanić 《International Journal of Hydrogen Energy》2007
The intermetallic phases along the Pt–Mo phase diagram, singly or in combination with specific ionic activators, have been investigated as cathode materials for the production of hydrogen by electrolysis from water KOH solutions in an attempt to decrease energy consumption. The influence of ionic activators (activating compounds) on energy consumption was significant. The intermetallic phases, as cathode materials, were activated by the surface deposition of activating compounds from electrolyte. The influence of these cathode materials on the electrolytic evolution of hydrogen was discussed in the context of transition metals features and their electronic configuration. 相似文献
4.
《Journal of power sources》2001,103(1):147-149
Fe–P and Fe–P–Pt alloys for use as electrodes for alkaline water electrolysis are prepared by an electroplating technique which employs an acidic complex bath solution. After heat treatment, the plated alloys act as effective electrocatalytic materials by lowering the hydrogen overpotential sufficiently. The improved electrocatalytic activity is due to an increase in effective surface area, a change in surface features upon heat treatment, and the presence of traces of platinum. Electrodes of the plated alloys are stable even in a highly corrosive electrolytic medium (6 M KOH). 相似文献
5.
A. Altamirano-Gutiérrez A.M. Fernández F.J. Rodríguez Varela 《International Journal of Hydrogen Energy》2013
In this work, we report the synthesis and characterization of unsupported Pt-CeO2 (1:1 wt. % Pt:CeO2 ratio) and Pt-Pd (1:1 wt. % Pt:Pd ratio) electrocatalysts as candidate cathodes for alkaline direct methanol fuel cells (A-DMFCs). The catalytic activity of the cathodes for the oxygen reduction reaction (ORR) in the absence and presence of methanol, in KOH as electrolyte, was evaluated at room temperature. The materials were prepared by chemical reduction with NaBH4, and pyrolysis at 300 and 600 °C under a H2/N2 atmosphere. The XRD results indicated the formation of polycrystalline materials with particle sizes ranging from 9 to 19 nm. Analysis by HRTEM showed the formation of nanostructures with lattice fringes corresponding to Pt, Pd (i.e., the Pt-Pd cathode), or CeO2 (i.e., the Pt-CeO2 material). The electrochemical characterization in 0.1 mol L−1 KOH showed that the Pt-Pd is highly active for the ORR in alkaline medium, delivering higher onset potential and mass activity than Pt-alone. Meanwhile, the Pt-CeO2 material showed slightly lower ORR mass activity than Pt. However, in the presence of methanol, the Pt-CeO2 nanocatalyst demonstrated significantly higher selectivity and tolerance capability to the alcohol than Pt and Pt-Pd. 相似文献
6.
The anodic and cathodic behaviours of aluminium, iron, mercury steel (HgSt), chrome-nickel steel (CrNiSt) and platinum have been studied in a 2N NaCl electrolyte (pH = 5) by means of electrolysis. The potentials of the cathodes and the theoretical and experimental discharge potentials of the systems have been determined. The cathodic and anodic overpotentials produced on Al, Fe, HgSt, CrNiSt and Pt were predicted against a platinum anode and a platinum cathode, respectively. The amounts of hydrogen gas produced at different times on the cathodes at a constant potential were measured and the hydrogen yield was calculated. From the data obtained, it is suggested that Pt anode and Al or HgSt cathode, or Al anode and Pt cathode, couples should be employed for the best electrolysis system. 相似文献
7.
《International Journal of Hydrogen Energy》1998,23(4):253-257
A composite electrode as hydrogen cathodes composed of Ti2Ni hydrogen absorbing alloys and a Ni-Mo electrocatalyst was prepared for alkaline water electrolysis. The electrocatalytic properties of hydrogen evolution reaction (HER) are carried out in a 30 wt% KOH solution at 70 °C. The surface morphology and chemical composition of the cathode were also examined. The experimental results show that the composite cathode has a low hydrogen overpotential (ca. 60 mV at 70 °C in 30 wt% KOH) and excellent stability under conditions of continuous electrolysis and intermittent electrolysis with power interruption shutdown. The stability mechanism of the cathode against intermittent electrolysis is discussed. 相似文献
8.
《International Journal of Hydrogen Energy》2001,26(2):127-132
In this study, two integrated PV/electrolysis systems were studied. An integrated PV/electrolysis device is a device where the PV system and the electrolyser are combined into a single system. In the case studied here, the areas of the PV device and the electrolyzer are identical. Multijunction photovoltaic (PV)/electrolysis configurations were investigated, and a high solar-to-hydrogen conversion efficiency cell demonstrated. The energy diagram of the configuration has been evaluated and exemplified with n/p, n/p-GaInP/GaAs(Pt)/KOH electrolyte and triple-junction p–i–n a-Si(Pt)/KOH electrolyte photovoltaic/electrolysis cells. The efficiency of the cells was determined based on the short-circuit photocurrent. Measurements were obtained both indoors under 100-mW/cm2 insolation, and outdoors. For the a-Si system, a 7.8% solar-to-hydrogen conversion efficiency was demonstrated. For the GaAs/GaInP2 system, the solar-to-hydrogen conversion efficiency was over 16%. 相似文献
9.
N.M. Sánchez-Padilla D. Morales-Acosta M.D. Morales-Acosta S.M. Montemayor F.J. Rodríguez-Varela 《International Journal of Hydrogen Energy》2014
We report the performance of M@Pt (M = Pd, Fe3O4, Ru) core–shell nanostructures for the ORR in H2SO4. The nanomaterials were rapidly synthesized in a total of 120 s applying magnetic (MS), mechanical (UT) and sonochemical (USS) stirring. Pt-alone nanoparticles were also synthesized by UT and served as a reference to evaluate the performance of the core–shell cathodes. Crystalline features were obtained from the Pd and the Fe3O4 cores, while Ru cores apparently having quasi-amorphous characteristics or too small particle sizes were formed. Nevertheless, the three core–shell materials showed crystalline Pt features. From Scherrer analysis, it was determined that core–shell nanostructures with particle sizes from 7.3 to 9.2 nm were formed. The electrochemical characterization confirmed that active core–shell cathodes were obtained, with two of the Pd@Pt materials showing catalytic activities as high as that of the Pt-alone nanoparticles, or even higher in terms of mass activity. XPS analysis indicated that mainly Pt(0) species were formed at the cathodes, along with Pt(II) and Pt(IV). It was found that catalysts with high Pt(IV):Pt(II) showed enhanced catalytic activity for the reduction of oxygen. In the presence of ethanol, the evaluated Pd@Pt cathode showed the higher selectivity towards the ORR compared to the other cathodes. 相似文献
10.
《International Journal of Hydrogen Energy》1986,11(6):389-397
The H2 storage characteristics of certain Ti-based transition metal alloys, containing Mg, Co, Fe and Ni were investigated by the electrochemical generation of H2 using alloy specimens as cathodes in an electrochemical cell. Metallographic evaluation of the cathodes indicates that alloy composition, rate of electrolysis, mechanical strength and stability of the alloys are interrelated. These properties may be advantageously regulated by the electrolytic current density which controls the rate of H2 formation per unit area of the alloy. The results are of potential usefulness for the rational design of H2 storage devices of a chemo-metallurgical nature. 相似文献
11.
Composite cathode based on La0.75Sr0.25Cr0.5Mn0.5O3−δ (LSCM) can be utilized for direct steam electrolysis in an oxide-ion conducting solid oxide electrolyzer; however, the insufficient electro-catalytic activity of LSCM still restricts the electrode performance and the Faraday efficiency. In this work, catalytic-active Ni particles are loaded to cathode via impregnation method. The electrical properties of LSCM are investigated and further correlated to the electrochemical performance of LSCM-SDC cathodes. The AC impedance spectroscopy and current–voltage tests demonstrate that the electrochemical reduction of LSCM cathodes is the main process at low voltages; however, the steam electrolysis is the dominant process at high voltages. The Faraday efficiency with Ni-loaded LSCM was enhanced by 20% in 4.96%H2/Ar/3%H2O and 11% in 97%Ar/3%H2O in contrast to the bare LSCM-SDC cathodes, respectively. The synergetic effect of catalytic-active Ni and redox-stable LSCM contributes to improved performance and the stability of the cathode for direct steam electrolysis. 相似文献
12.
Yu-Xi HuangXian-Wei Liu Xue-Fei SunGuo-Ping Sheng Yuan-Yuan ZhangGuo-Ming Yan Shu-Guang WangAn-Wu Xu Han-Qing Yu 《International Journal of Hydrogen Energy》2011,36(4):2773-2776
Microbial electrolysis cell (MEC) provides a sustainable way for hydrogen production from organic matters, but it still suffers from the lack of efficient and cost-effective cathode catalyst. In this work carbon paper coated with Pd nanoparticles was prepared using electrochemical deposition method and used as the cathodic catalyst in an MEC to facilitate hydrogen production. The electrode coated with Pd nanoparticles showed a lower overpotential than the carbon paper cathode coated with Pt black. The coulombic efficiency, cathodic and hydrogen recoveries of the MEC with the Pd nanoparticles as catalyst were slightly higher than those with a Pt cathode, while the Pd loading was one order of magnitude less than Pt. Thus, the catalytic efficiency normalized by mass of the Pd nanoparticles was about fifty times higher than that of the Pt black catalyst. These results demonstrate that utilization of the cathode with Pd nanoparticles could greatly reduce the costs of the cathodic catalysts when maintaining the MEC system performance. 相似文献
13.
I. Kruusenberg L. Matisen Q. Shah A.M. Kannan K. Tammeveski 《International Journal of Hydrogen Energy》2012
Hydrogen–oxygen fuel cells using an alkaline anion exchange membrane were prepared and evaluated. Various non-platinum catalyst materials were investigated by fabricating membrane-electrode assemblies (MEAs) using Tokuyama membrane (# A201) and compared with commercial noble metal catalysts. Co and Fe phthalocyanine catalyst materials were synthesized using multi-walled carbon nanotubes (MWCNTs) as support materials. X-ray photoelectron spectroscopic study was conducted in order to examine the surface composition. The electroreduction of oxygen has been investigated on Fe phthalocyanine/MWCNT, Co phthalocyanine/MWCNT and commercial Pt/C catalysts. The oxygen reduction reaction kinetics on these catalyst materials were evaluated using rotating disk electrodes in 0.1 M KOH solution and the current density values were consistently higher for Co phthalocyanine based electrodes compared to Fe phthalocyanine. The fuel cell performance of the MEAs with Co and Fe phthalocyanines and Tanaka Kikinzoku Kogyo Pt/C cathode catalysts were 100, 60 and 120 mW cm−2 using H2 and O2 gases. 相似文献
14.
Demétrius W. Lima Fernanda Fiegenbaum Fernanda Trombetta Michèle O. de Souza Emilse M.A. Martini 《International Journal of Hydrogen Energy》2018,43(3):1239-1250
Vitreous carbon (VC), pyrolytic carbon (PC) and moulded graphite (MG) were tested as cathodic materials in hydrogen production by water electrolysis in the presence of the ionic liquid tetrafluoroborate of 3-triethylammonium-propane sulfonic acid (TEA-PS.BF4). The physical characterization of the carbon materials indicated large differences in the microstructure of VC, PC, and MG and this significantly affected their electrochemical response. The mechanism presented for all the materials studied in the hydrogen evolution reaction (HER) was Volmer–Heyrovsky, where the H2 desorption at the catalytic surface is the determining step. The MG electrode presented an unfavourable performance due to the formation of nanobubbles that coalesced without H2 desorption and led to the deactivation of the catalytic sites. This behaviour is attributed to the presence of large and ordered crystallites at the material surface, with a greater number of hydrophobic domains in comparison with VC and PC material surfaces. The VC and PC electrodes presented a higher performance compared to the Pt cathode, showing lower activation energy, higher cathodic exchange current and lower charge transfer resistance. The set of results indicates VC and PC as promising alternative materials to constitute cathodes for the electrolysis of water using TEA-PS.BF4 aqueous solution as electrolyte. 相似文献
15.
《International Journal of Hydrogen Energy》2021,46(79):39136-39145
An affordable cathode material for microbial electrolysis cells (MECs) was synthesized via surface-modification of stainless steel mesh (SSM) by anodization. The anodization parameters, such as wire mesh size, temperature, applied voltage, operating time, were optimized. The surface-modified SSM (smSSM) exhibited porous surface and higher specific surface area. The as synthesized smSSMs were utilized as freestanding cathodes in a conventional microbial electrolysis cell (MEC) and a simultaneous dark fermentation and MEC process (sDFMEC). The H2 production in MEC and sDFMEC with smSSM as cathode was approximately 150% higher than that with SSM. The performance of smSSM was 67–75% of that of Pt/C. The sDFMEC with smSSM as cathode was stable for 12 cycles of fed-batch operation in 60 days. Overall, energy conversion from S. japonica by sDFMEC was as high as 23.4%. 相似文献
16.
D.E. Brown M.N. Mahmood A.K. Turner S.M. Hall P.O. Fogarty 《International Journal of Hydrogen Energy》1982,7(5):405-410
An electrocatalyst for hydrogen evolving cathodes has been developed for use in alkaline media. The materials employed in manufacturing the coating are relatively cheap transition metals. The results of a variety of performance tests are reported. The electrodes exhibit a low overvoltage for hydrogen evolution (70–90 mV at 70°C and 1A cm?2 in 5 N KOH), stability to abuse (e.g. current interruption or reversal) and a long cathode life under operating conditions. 相似文献
17.
《International Journal of Hydrogen Energy》2020,45(58):33968-33979
The present work focuses on the optimization of operating parameters using Box Behnken design (BBD) in RSM to obtain maximum power density from a glycerol based air-breathing T-shaped MFC. The major parameters influencing the experiment for enhancing the cell performance in MFC are glycerol/fuel concentration, anode electrolyte/KOH concentration, anode electrocatalyst loading and cathode electrolyte/KOH concentration. The ambient oxygen is used as the oxidant. The acetylene black carbon (CAB) supported laboratory synthesized electrocatalyst Pd–Pt (16:4)/CAB is used as anode electrocatalyst and commercial Pt (40 wt%)/CHSA as the cathode electrocatalyst. The quadratic model predicts the appropriate operating conditions to achieve highest power density from the laboratory designed T-shaped MFC. The p-value of less than 0.0001 and F-value of greater than 1 i.e., 26.32 indicate that the model is significant. The optimum conditions predicted by the RSM model were glycerol concentration of 1.07 M, anode electrolyte concentration of 1.62 M anode electrocatalyst loading of 1.12 mg/cm2 and cathode electrolyte concentration of 0.69 M. The negligible deviation of only 1.07% between actual/experimental power density (2.76 mW/cm2) and predicted power density (2.79 mW/cm2) was recorded. This model reasonably predicts the optimum conditions using Pd–Pt (16:4)/CAB electrocatalyst to obtain maximum power density from glycerol based MFC. 相似文献
18.
Alberto Tenca Roland D. Cusick Andrea Schievano Roberto Oberti Bruce E. Logan 《International Journal of Hydrogen Energy》2013
Microbial electrolysis cells (MECs) can be used to treat wastewater and produce hydrogen gas, but low cost cathode catalysts are needed to make this approach economical. Molybdenum disulfide (MoS2) and stainless steel (SS) were evaluated as alternative cathode catalysts to platinum (Pt) in terms of treatment efficiency and energy recovery using actual wastewaters. Two different types of wastewaters were examined, a methanol-rich industrial (IN) wastewater and a food processing (FP) wastewater. The use of the MoS2 catalyst generally resulted in better performance than the SS cathodes for both wastewaters, although the use of the Pt catalyst provided the best performance in terms of biogas production, current density, and TCOD removal. Overall, the wastewater composition was more of a factor than catalyst type for accomplishing overall treatment. The IN wastewater had higher biogas production rates (0.8–1.8 m3/m3-d), and COD removal rates (1.8–2.8 kg-COD/m3-d) than the FP wastewater. The overall energy recoveries were positive for the IN wastewater (3.1–3.8 kWh/kg-COD removed), while the FP wastewater required a net energy input of −0.7–−1.2 kWh/kg-COD using MoS2 or Pt cathodes, and −3.1 kWh/kg-COD with SS. These results suggest that MoS2 is the most suitable alternative to Pt as a cathode catalyst for wastewater treatment using MECs, but that net energy recovery will be highly dependent on the specific wastewater. 相似文献
19.
Takaaki Sakai Shotaro Matsushita Hiroshige Matsumoto Sachio Okada Shinichi Hashimoto Tatsumi Ishihara 《International Journal of Hydrogen Energy》2009
Steam electrolysis using SrZr0.9Y0.1O3-α (SZY-91) electrolyte was investigated. Different electrode materials, i.e., porous platinum, Sr0.5Sm0.5CoO3 (SSC-55) for the anode and nickel for the cathode were examined in order to achieve better energy performance. The electrodes had poor electrode activity when platinum was used for both the anode and the cathode, while the SSC-55 anode displayed significantly low overpotentials and the nickel cathode exhibited low overpotentials upon the introduction of an SrCe0.95Yb0.05O3-α (SCYb) interlayer. Moreover, a partial substitution of cerium for zirconium in the strontium zirconate electrolyte, i.e., SrZr0.5Ce0.4Y0.1O3-α (SZCY-541), was found to be effective for improving the current efficiency of the hydrogen evolution rate. Accordingly, the cell SSC-55|SZCY-541|SCYb|Ni exhibited much higher energy efficiency for the steam electrolysis than the Pt|SZY-91|Pt cell. 相似文献
20.
Sophie von Kraemer Kjell Wikander Göran Lindbergh Anders Lundblad Anders E.C. Palmqvist 《Journal of power sources》2008
Anatase TiO2 is evaluated as catalyst support material in authentic Pt-TiO2/C composite gas diffusion electrodes (GDEs), as a different approach in the context of improving the proton exchange membrane fuel cell (PEMFC) cathode stability. A thermal stability study shows high carbon stability as Pt nanoparticles are supported on TiO2 instead of carbon in the Pt-TiO2/C composite material, presumably due to a reduced direct contact between Pt and C. The performance of Pt-TiO2/C cathodes is investigated electrochemically in assembled membrane-electrode assemblies (MEAs) considering the added carbon fraction and Pt concentration deposited on TiO2. The O2 reduction current for the Pt-TiO2 alone is expectedly low due to the low electronic conductivity in bulk TiO2. However, the Pt-TiO2/C composite cathodes show enhanced fuel cell cathode performance with growing carbon fraction and increasing Pt concentration deposited on TiO2. The proposed reasons for these observations are improved macroscopic and local electronic conductivity, respectively. Electron micrographs of fuel cell tested Pt-TiO2/C composite cathodes illustrate only a minor Pt migration in the Pt-TiO2/C structure, in which anatase TiO2 is used as Pt support. On the whole, the study demonstrates a stable Pt-TiO2/C composite material possessing a performance comparable to conventional Pt–C materials when incorporated in a PEMFC cathode. 相似文献