scholarly journals FeNxC Based Catalysts Prepared by the Calcination of Iron-Ethylenediamine@Polyaniline as the Cathode-Catalyst of Proton Exchange Membrane Fuel Cell

Polymers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1368 ◽  
Author(s):  
Yen-Zen Wang ◽  
Wen-Yao Huang ◽  
Tar-Hwa Hsieh ◽  
Li-Cheng Jheng ◽  
Ko-Shan Ho ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Power Density ◽  
Active Sites ◽  
Proton Exchange Membrane ◽  
Reduction Reaction ◽  
High Specific Surface Area ◽  
Proton Exchange ◽  
Metal Catalyst ◽  
Durability Test ◽  
Redox Cycles

Calcinated tris(ethylenediamine)iron(III) chloride was used as a non-precious metal catalyst (NPMCs) for a proton exchanged membrane fuel cell (PEMFC) under the protection of polyaniline (PANI), which behaves as both nitrogen source and carbon supporter. The optimal ratio of FeCl3/EDA was found to be close to 1/3 under the consideration of the electrocatalytic performance, such as better oxygen reduction reaction (ORR) and higher power density. Two-stage calcination, one at 900 °C in N2 and the other at 800 °C in mixed gases of N2 and NH3, result in an FeNxC catalyst (FeNC-900-800-A) with pretty high specific surface area of 1098 m2·g−1 covered with both micro- and mesopores. The ORR active sites focused mainly on Fe–Nx bonding made of various pyridinic, pyrrolic, and graphitic N-s after calcination. The max. power density reaches 140 mW·cm−2 for FeNC-900-800-A, which is superior to other FeNxC catalysts, experiencing only one-stage calcination in N2. The FeNxC demonstrates only 10 mV half-wave-voltage (HWV) loss at 1600 rpm after 1000 redox cycles, as compared to be 27 mV for commercial Pt/C catalyst in the durability test.

scholarly journals Intermetallic Platinum Alloy Nanoparticles and Single Atoms Hybrid Electrocatalysts for Proton Exchange Membrane Fuel Cells

2021 ◽  
Author(s):  
Minhua Shao ◽  
Fei Xiao ◽  
Qi Wang ◽  
Gui-Liang Xu ◽  
Xueping Qin ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Active Sites ◽  
Proton Exchange Membrane ◽  
Synergistic Effects ◽  
Reduction Reaction ◽  
Proton Exchange ◽  
Alloy Nanoparticles ◽  
Single Atoms ◽  
Low Pt Loading ◽  
Exchange Membrane

Abstract Proton exchange membrane fuel cell converts hydrogen and oxygen into electricity with zero emission1. The high cost and low durability of Pt-based electrocatalysts for oxygen reduction reaction hinder its wide applications2,3. The development of non-precious metal electrocatalysts also reaches the bottleneck because of the low activity and durability4,5. Here we rationally design a hybrid electrocatalyst consisting of atomically dispersed Pt and Fe single atoms and intermetallic PtFe alloy nanoparticles. The Pt mass activity of the hybrid catalyst is 3.5 times higher than that of commercial Pt/C in a fuel cell. More importantly, the fuel cell with an ultra-low Pt loading in the cathode (0.015 mgPt cm-2) shows unprecedented durability, with 93.6% activity retention after 100,000 cycles and no noticeable current drop at 0.6 V for at least 206 h. These results highlight the importance of the synergistic effects among active sites in hybrid electrocatalysts and provide an alternative way to design more active and durable low-Pt electrocatalysts for electrochemical devices.

scholarly journals Degradation and regeneration of Fe-Nx active sites for oxygen reduction reaction: the role of surface oxidation, Fe demetallation and local carbon microporosity

2021 ◽  
Author(s):  
Dongsheng Xia ◽  
Chenchen Yu ◽  
Yinghao Zhao ◽  
Yinping Wei ◽  
Haiyan Wu ◽  
...  
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Active Sites ◽  
Proton Exchange Membrane ◽  
Degradation Mechanism ◽  
Surface Oxidation ◽  
Reduction Reaction ◽  
Proton Exchange ◽  
Exchange Membrane

The severe degradation of Fe-N-C electrocatalysts during long-term oxygen reduction reaction (ORR) has become a major obstacle for application in proton-exchange membrane fuel cells. Understanding the degradation mechanism and regeneration...

Optimum Design and Performance Simulation of a Multi-device Integrated System Based on a Proton Exchange Membrane Fuel Cell

2022 ◽  
pp. 1-33
Author(s):  
Xiuqin Zhang ◽  
Wentao Cheng ◽  
Qiubao Lin ◽  
Longquan Wu ◽  
Junyi Wang ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Power Density ◽  
Power Output ◽  
Proton Exchange Membrane ◽  
Waste Heat ◽  
Proton Exchange ◽  
Integrated System ◽  
Interior Space ◽  
And Performance ◽  
Exchange Membrane

Abstract Proton exchange membrane fuel cells (PEMFCs) based on syngas are a promising technology for electric vehicle applications. To increase the fuel conversion efficiency, the low-temperature waste heat from the PEMFC is absorbed by a refrigerator. The absorption refrigerator provides cool air for the interior space of the vehicle. Between finishing the steam reforming reaction and flowing into the fuel cell, the gases release heat continuously. A Brayton engine is introduced to absorb heat and provide a useful power output. A novel thermodynamic model of the integrated system of the PEMFC, refrigerator, and Brayton engine is established. Expressions for the power output and efficiency of the integrated system are derived. The effects of some key parameters are discussed in detail to attain optimum performance of the integrated system. The simulation results show that when the syngas consumption rate is 4.0 × 10−5 mol s−1cm−2, the integrated system operates in an optimum state, and the product of the efficiency and power density reaches a maximum. In this case, the efficiency and power density of the integrated system are 0.28 and 0.96 J s−1 cm−2, respectively, which are 46% higher than those of a PEMFC.

The Effect of Inlet Parameters on Fluid Flow and Cell Performance at Cathode of a Proton Exchange Membrane Fuel Cell

2010 ◽  
Vol 7 (4) ◽  
Author(s):  
Utku Gulan ◽  
Hasmet Turkoglu ◽  
Irfan Ar
Keyword(s):  
Reynolds Number ◽  
Fuel Cell ◽  
Power Density ◽  
Current Density ◽  
Proton Exchange Membrane ◽  
Catalyst Layer ◽  
Pem Fuel Cell ◽  
Proton Exchange ◽  
Exchange Membrane ◽  
Oxygen Mole Fraction

In this study, the fluid flow and cell performance in cathode side of a proton exchange membrane (PEM) fuel cell were numerically analyzed. The problem domain consists of cathode gas channel, cathode gas diffusion layer, and cathode catalyst layer. The equations governing the motion of air, concentration of oxygen, and electrochemical reactions were numerically solved. A computer program was developed based on control volume method and SIMPLE algorithm. The mathematical model and program developed were tested by comparing the results of numerical simulations with the results from literature. Simulations were performed for different values of inlet Reynolds number and inlet oxygen mole fraction at different operation temperatures. Using the results of these simulations, the effects of these parameters on the flow, oxygen concentration distribution, current density and power density were analyzed. The simulations showed that the oxygen concentration in the catalyst layer increases with increasing Reynolds number and hence the current density and power density of the PEM fuel cell also increases. Analysis of the data obtained from simulations also shows that current density and power density of the PEM fuel cell increases with increasing operation temperature. It is also observed that increasing the inlet oxygen mole fraction increases the current density and power density.

scholarly journals MOF Derived Catalysts for Oxygen Reduction Reaction in Proton Exchange Membrane Fuel Cell

2018 ◽  
Vol 778 ◽  
pp. 275-282
Author(s):  
Noaman Khan ◽  
Saim Saher ◽  
Xuan Shi ◽  
Muhammad Noman ◽  
Mujahid Wasim Durani ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Membrane Electrode Assembly ◽  
Reduction Reaction ◽  
Proton Exchange ◽  
Membrane Electrode ◽  
Nitrogen Doped ◽  
Nitrogen Doped Carbon ◽  
Exchange Membrane

Highly porous ZIF-67 (Zeolitic imidazole framework) has a conductive crystalline metal organic framework (MOF) structure which was served as a precursor and template for the preparation of nitrogen-doped carbon nanotubes (NCNTs) electrocatalysts. As a first step, the chloroplatinic acid, a platinum (Pt) precursor was infiltrated in ZIF-67 with a precise amount to obtain 0.12 mg.cm-2 Pt loading. Later, the infiltrated structure was calcined at 700°C in Ar:H2 (90:10 vol%) gas mixture. Multi-walled nitrogen-doped carbon nanotubes were grown on the surface of ZIF-67 crystals following thermal activation at 700°C. The resulting PtCo-NCNTs electrocatalysts were deposited on Nafion-212 solid electrolyte membrane by spray technique to study the oxygen reduction reaction (ORR) in the presence of H2/O2 gases in a temperature range of 50-70°C. The present study elucidates the performance of nitrogen-doped carbon nanotubes ORR electrocatalysts derived from ZIF-67 and the effects of membrane electrode assembly (MEA) steaming on the performance of proton exchange membrane fuel cell (PEMFC) employing PtCo-NCNTs as ORR electrocatalysts. We observed that the peak power density at 70°C was 450 mW/cm2 for steamed membrane electrode assembly (MEA) compared to 392 mW/cm2 for an identical MEA without steaming.

scholarly journals ELECTROCHEMICAL ACTIVITY OF PtM (M=Co, Cu, Ni) CATALYSTS SUPPORTED ON CARBON VULCAN FOR OXYGEN REDUCTION REACTION (ORR) IN FUEL CELLS

2018 ◽  
Vol 56 (2A) ◽  
pp. 81-88 ◽  
Author(s):  
Vu Thi Hong Phuong
Keyword(s):  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Chemical Reduction ◽  
Low Cost ◽  
Reduction Reaction ◽  
Proton Exchange ◽  
Carbon Powder ◽  
Galvanic Replacement ◽  
H2o2 Formation ◽  
Cost Efficient

PEMFC - proton exchange membrane fuel cell is electrochemical devices producing electricity and heat from reaction between a fuel (often hydrogen) and oxygen. Therefore, energy production is generally clean and effective without burning the fuel like the tradition way in combustion engines. The obstacles encountered fuel cell commercialization are mainly due to expensive catalyst materials (Platinum) and long-term instability performance. For this reason, numerous investigations have been undertaken with the goal of developing low-cost, efficient electrocatalysts that can be used as alternatives to Pt. In this paper, a two-step procedure at room temperature was applied to prepare a bimetallic Pt-M(M = metal) supported carbon Vulcan. First, the chemical reduction of M metal ions by sodium borohydride in the presence of carbon powder is performed. Second, the partial galvanic replacement of M particle layers by Pt is achieved upon immersion in a chloroplatinate solution. The major size of synthesized metallic particles was around 2-3 nm. From the slope of Koutecky-Levich plot for ORR using PtM/C materials as catalysts it was found that the overall electron transfer number ranged from 3 to 4, leading to the suggestion of H2O2 formation as an intermediate of the ORR.

Non Precious Metal Catalysts: A Fuel Cell and ORR Study of Thermally Synthesized Nickel and Platinum Mixed Nickel Nanotubes for PEMFC

2021 ◽  
Vol 875 ◽  
pp. 193-199
Author(s):  
Ahmad Shahbaz ◽  
Ali Afaf ◽  
Nawaz Tahir ◽  
Ullah Abid ◽  
Saher Saim
Keyword(s):  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Rotating Disk ◽  
Platinum Group Metal ◽  
Catalytic Performance ◽  
Reduction Reaction ◽  
Proton Exchange ◽  
Rotating Disk Electrode ◽  
Highly Active ◽  
Precious Metal Catalysts

A highly active Platinum Group Metal (PGM) and non-PGM electrocatalysts with thermally extruded nanotubes have been prepared for Proton Exchange Membrane (PEM) fuel cell by sintering Nickel zeolitic imidazole framework (Ni-ZIF). Preeminent electro-catalytic activities have been observed through single fuel cell tests and rotating disk electrode (RDE). This study involves the comparison of Oxygen Reduction Reaction (ORR) activities and fuel cell (FC) test station performance of two catalyst Nickel and Platinum mixed Nickel nanotubes (Ni NT, Ni/Pt NT) respectively. The acidic cells with corresponding Ni and Ni/Pt catalysts delivers peak power densities of 325 mWcm-2 and 455 mWcm-2 at 75 °C inside fuel cell. Our results indicate that, the synthesized Nickel nanotubes has profound effect on catalytic performance of both PGM and non-PGM electro catalysts.

An Experimental Study of the Effect of a Turbulence Grid on the Stack Performance of an Air-Cooled Proton Exchange Membrane Fuel Cell

2019 ◽  
Vol 17 (1) ◽  
Author(s):  
Saher Al Shakhshir ◽  
Xin Gao ◽  
Torsten Berning
Keyword(s):  
Heat Transfer ◽  
Fuel Cell ◽  
Power Density ◽  
Proton Exchange Membrane ◽  
Numerical Study ◽  
Proton Exchange ◽  
Limiting Current ◽  
Cathode Side ◽  
Exchange Membrane ◽  
Turbulence Grid

Abstract In a previous numerical study on heat and mass transfer in air-cooled proton exchange membrane fuel cells, it was found that the performance is limited by heat transfer to the cathode side air stream that serves as a coolant, and it was proposed to place a turbulence grid before the cathode inlet in order to induce a mixing effect to the air and thereby improve the heat transfer and ultimately increase the limiting current and maximum power density. The current work summarizes experiments with different turbulence grids which varied in terms of their pore size, grid thickness, rib width, angle of the pores, and the distance between the grid and the cathode inlet. For all grids tested in this study, the limiting current density of a Ballard Mark 1020 ACS stack was increased by 20%. The single most important parameter was the distance between the turbulence grid and the cathode inlet, and it should be within 5 mm. For the best grid tested, the fuel cell stack voltage and thus the efficiency were increased by up to 20%. The power density was increased by more than 30% and further improvements are believed to be possible.

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