Papers by Biraj Kumar Kakati
International Journal of Hydrogen Energy, 2016
Sulphur dioxide (SO2) is a common atmospheric contaminant which has a deleterious effect on fuel ... more Sulphur dioxide (SO2) is a common atmospheric contaminant which has a deleterious effect on fuel cells. The performance of a Polymer Electrolyte Fuel Cell (PEFC) utilising a Pt on nitrogen doped graphene support as the cathode catalyst was studied in the presence of air contaminated with known levels of SO 2. The nitrogen doped graphene supported platinum was synthesized by a hydrothermal method. At levels of 25 ppm SO 2 in air there was within 15 min a 28% reduction in the PEFC performance at 0.5 V. The performance degradation was more severe at higher SO 2 concentrations. At 100 ppm SO 2 in air the performance degraded by 91% at the same potential. The power loss of the fuel cell could not be recovered by externally polarising the PEFC at 1.6 V. Even after continuous potential cycling of the cell for 9 h only 80% of the initial performance could be recovered. However, a 15 min treatment with 0.4% O 3 in air showed almost a 100% performance recovery of the 100 ppm SO 2 contaminated fuel cell. The enhanced recovery of the fuel cell is related both to the chemical reaction of O 3 with the adsorbed sulphur contaminant, and an increase of cathode potential during the electrochemical treatment.
Materials Today: Proceedings, 2022
Nitrogen-doped (N-G) and sulfur-nitrogen co-doped (SN-G) carbon-based electrocatalysts from two d... more Nitrogen-doped (N-G) and sulfur-nitrogen co-doped (SN-G) carbon-based electrocatalysts from two different biomass waste are successfully synthesized, and their ORR catalytic activity is also examined. In this research work, a simple preparation route for the synthesis of N-G catalyst from rice straw as a carbon source and urea as a nitrogen source is developed. Another facile route is developed for the synthesis of SN-G catalyst from reeling waste of muga silk (Anthraea assamensis) and thiourea (N and S source). Synthesized catalysts are characterized thoroughly for composition and microstructure details using XRD, Raman spectroscopy, FT-IR, FESEM, XPS, and BET surface area analyzer. The XPS analyses of the synthesized N-G and SN-G catalysts revealed that the nitrogen contents in both the catalysts are 0.85 and 14.85 At. %, respectively. Simultaneously, the sulfur content in the SN-G catalyst is found to be 2.94 At. %. Cyclic voltammetry is used for the evaluation of the catalytic activity of the catalysts towards ORR reaction in oxygen saturated 0.1 M KOH solution.
Sustainable Materials and Technology, 2022
Journal of Environmental Research and Development, 2009
With the shortage of oil and gas resources and global climate change emerging as high concerns, t... more With the shortage of oil and gas resources and global climate change emerging as high concerns, the need for new technologies to alleviate the dependence on hydrocarbons and reduced carbon dioxide (CO2) emissions is becoming stringent. Considerable efforts have been given to develop commercially viable technologies to reduce the CO2 emission by the use of fossil fuel, producing hydrogen from fossil fuel, using nuclear and renewable energy sources and to develop fuel cells. Among all the energy sources fuel cells are getting importance as one of the most promising clean energy sources for stationary as well as automotive application. Considerable efforts have been given worldwide for the development of cost-effective fuel cells. Bipolar plate is one of the key components of the fuel cell, which consumes around 38% of the total cost and contributes around 80% of the total stack weight. In this study composite bipolar plates for proton exchange membrane fuel cell (PEMFC) were developed by compression molding technique using vinyl ester resin as a polymer matrix and natural graphite as reinforcement. U.S. Department of Energy (US DOE) target values were taken as the benchmark for the development and investigation of the bipolar plate. The composite bipolar plates were characterized for density, porosity, electrical conductivity, flexural strength, shore hardness and corrosion resistance. At 25% resin content the composite bipolar plate achieved the US DOE benchmark for density, electrical conductivity, shore hardness and corrosion resistance. However, the flexural strength of the composite bipolar plate was not up to the benchmark set by the US DOE.
Proceedings of ASME 2011 5th International Conference on Energy Sustainability & 9th Fuel Cell Science, Engineering and Technology Conference, 2011
Composite bipolar plates for polymer electrolyte membrane fuel cell (PEMFC) were developed by com... more Composite bipolar plates for polymer electrolyte membrane fuel cell (PEMFC) were developed by compression molding technique using vinyl ester resin as a binder and natural graphite, carbon black, and carbon fiber as conductive reinforcements. The developed bipolar plates were characterized for electrical conductivity, flexural strength, deflection at mid-span, hydrogen permeability, and morphology. The in-plane and through-plane electrical conductivities of the composite bipolar plate (VER:25%;CB:5%;CF:5%;NG:65%) were 355.05 and 95.96 S•cm −1 , respectively. The flexural strength of the same bipolar plate was 53.50 MPa with a deflection of 5.37%. The hydrogen permeability of the bipolar plate was in the order of 10 −9 cm 3 •cm −1 •s −1 at 50°C. The overall properties of the composite bipolar plate were found to achieve the benchmark set by USA-Department of Energy. However, the through-plane electrical conductivity of the above composite was edge below the target value. Therefore, graphene, being one of the most electrical conductive materials, has been reinforced into the composite bipolar plate. The results were very encouraging as 1% graphene reinforcement increased the in-plane and throughplane electrical conductivities of the bipolar plate by around 6 and 35%, respectively. The performance of a PEMFC was evaluated using the developed bipolar plate in in-situ condition.
Materials Today: Proceedings, 2022
Nitrogen-doped (N-G) and sulfur-nitrogen co-doped (SN-G) carbon-based electrocatalysts from two d... more Nitrogen-doped (N-G) and sulfur-nitrogen co-doped (SN-G) carbon-based electrocatalysts from two different biomass waste are successfully synthesized, and their ORR catalytic activity is also examined. In this research work, a simple preparation route for the synthesis of N-G catalyst from rice straw as a carbon source and urea as a nitrogen source is developed. Another facile route is developed for the synthesis of SN-G catalyst from reeling waste of muga silk (Anthraea assamensis) and thiourea (N and S source). Synthesized catalysts are characterized thoroughly for composition and microstructure details using XRD, Raman spectroscopy, FT-IR, FESEM, XPS, and BET surface area analyzer. The XPS analyses of the synthesized N-G and SN-G catalysts revealed that the nitrogen contents in both the catalysts are 0.85 and 14.85 At. %, respectively. Simultaneously, the sulfur content in the SN-G catalyst is found to be 2.94 At. %. Cyclic voltammetry is used for the evaluation of the catalytic activity of the catalysts towards ORR reaction in oxygen saturated 0.1 M KOH solution.
Journal of Power Sources, Apr 1, 2014
The effect of hydrogen sulfide (H2S) on the anode of a polymer electrolyte membrane fuel cell (PE... more The effect of hydrogen sulfide (H2S) on the anode of a polymer electrolyte membrane fuel cell (PEMFC) and the gas phase recovery of the contaminated PEMFC using ozone (O3) were studied. Experiments were performed on fuel cell electrodes both in an aqueous electrolyte and within an operating fuel cell. The ex-situ analyses of a fresh electrode; a H2S contaminated electrode (23 μmolH2S cm−2); and the contaminated electrode cleaned with O3 shows that all sulfide can be removed within 900 s at room temperature. Online gas analysis of the recovery process confirms the recovery time required as around 720 s. Similarly, performance studies of an H2S contaminated PEMFC shows that complete rejuvenation occurs following 600-900 s O3 treatment at room temperature. The cleaning process involves both electrochemical oxidation (facilitated by the high equilibrium potential of the O3 reduction process) and direct chemical oxidation of the contaminant. The O3 cleaning process is more efficient than the external polarization of the single cell at 1.6 V. Application of O3 at room temperature limits the amount of carbon corrosion. Room temperature O3 treatment of poisoned fuel cell stacks may offer an efficient and quick remediation method to recover otherwise inoperable systems.
International Journal of Hydrogen Energy, Apr 1, 2016
Abstract Sulphur dioxide (SO 2 ) is a common atmospheric contaminant which has a deleterious effe... more Abstract Sulphur dioxide (SO 2 ) is a common atmospheric contaminant which has a deleterious effect on fuel cells. The performance of a Polymer Electrolyte Fuel Cell (PEFC) utilising a Pt on nitrogen doped graphene support as the cathode catalyst was studied in the presence of air contaminated with known levels of SO 2 . The nitrogen doped graphene supported platinum was synthesized by a hydrothermal method. At levels of 25 ppm SO 2 in air there was within 15 min a 28% reduction in the PEFC performance at 0.5 V. The performance degradation was more severe at higher SO 2 concentrations. At 100 ppm SO 2 in air the performance degraded by 91% at the same potential. The power loss of the fuel cell could not be recovered by externally polarising the PEFC at 1.6 V. Even after continuous potential cycling of the cell for 9 h only 80% of the initial performance could be recovered. However, a 15 min treatment with 0.4% O 3 in air showed almost a 100% performance recovery of the 100 ppm SO 2 contaminated fuel cell. The enhanced recovery of the fuel cell is related both to the chemical reaction of O 3 with the adsorbed sulphur contaminant, and an increase of cathode potential during the electrochemical treatment.
International Journal of Hydrogen Energy, Dec 1, 2007
Bipolar plate is an important key component of fuel cell on the basis of its manifold function. I... more Bipolar plate is an important key component of fuel cell on the basis of its manifold function. In this direction a lot of effort is going on worldwide to make lightweight and cost-effective bipolar plate for fuel cell application. In the present investigation effort was made to develop graphite-composites bipolar plate by compression molding technique to achieve the requisite goal. The composites plates were prepared by using different reinforcing fillers such as natural graphite, synthetic graphite, carbon black, carbon fibers with phenolic resin as polymer matrix precursor in its liquid and powder form. The composition of different filler constituent adjusted in between 5 and 40 vol%. The composite plates prepared with appropriate proportion of filler components were characterized for physical and mechanical properties. It is found that no single reinforcing filler constituent composites plate gives the requisite properties for being used as bipolar plate in the PEM fuel cell. The judicious combination of reinforcing constituents gives the properties which are required for bipolar plate to use in fuel cell. By controlling the ratio of reinforcing constituents, one can able to achieve properties such as bulk density ∼ 1.85 g cm −3 , electrical conductivity > 150 S cm −1 , shore hardness > 65, bending strength > 60 MPa, modulus > 10 GPa and compressive > 70 MPa by applying the pressure (100 kg cm −2) during compression molding. I .V characteristic of the composite bipolar plate, with optimum combination of reinforcing constituent, is found to be adequate as per the US-DOE target for composite bipolar plate.
corrosion current density of the composite in simulated rigorous PEMFC environment was still in t... more corrosion current density of the composite in simulated rigorous PEMFC environment was still in the order of 1 μA•cm −2. Similarly, the hydrogen permeability of the composite was also in the order of 10 −9 cm 3 •cm −1 •s −1 at 50°C. The overall properties of the graphene reinforced composites were well above the target values of the bipolar plates for PEMFC. A PEMFC setup was developed to study the performance of the developed bipolar plates in real fuel cell. The use of graphene in the composite bipolar plates also showed around 10% improvement in the power density of the PEMFC. The peak power density of the PEMFC with the optimum composition of the NG/CB/CF/resol-PF composite bipolar plates was 397 mW•cm −2 at a current density of 752 mA•cm −2. The reinforcement with 1% graphene to the above composite bipolar plates increased the peak power density of the PEMFC to 437 mW•cm −2 at a current density of 827 mA•cm −2 .
Lecture notes in mechanical engineering, Sep 9, 2022
Materials Today: Proceedings, 2021
Materials Today: Proceedings, 2021
Materials Today: Proceedings, 2021
Abstract The rise in electrical energy demand and environmental concern results in shifting the w... more Abstract The rise in electrical energy demand and environmental concern results in shifting the world’s focus towards sustainable energy sources. Over-reliance of conventional fossil fuel-based power generation can be combatted using new and potential technologies like Microbial Fuel cells (MFCs). Direct conversion of chemical energy to electrical energy by the application of the naturally found microorganisms, makes MFC more convenient source of energy generation. Despite having low power density, it has been able to grab the researcher’s attention due to the flexibility of usage of various organic substrates. This review discusses the various households and industrial waste substrate which has further potential to generate power. The various liquid and solid substrates have been analysed and summarized. The substrate used, power densities, reactor volumes and specific important features used by the researchers for the improved performance have been tabulated. In a higher number of researches, liquid substrates have been comparatively more used than that of the solid substrates. Ease of handling, storage and accessibility of the liquid waste could be one of the few reasons for it. Also, in this review, various components, and key factors for the experimental design of MFC has been discussed. Along with that losses associated with MFCs and its application is explored.
IOP Conference Series: Earth and Environmental Science, 2019
The fuel cell and electrolyzer together may be an important alternative source for clean energy p... more The fuel cell and electrolyzer together may be an important alternative source for clean energy production. The oxygen-hydrogen produced in the water splitting reaction in an electrolyzer may also be used in any conventional combustion engines with a little or no modification of the existing engines. The sluggish oxygen reduction reaction (ORR) in these devices necessitates higher loading of catalysts in the cathode. However, the best catalyst used in fuel cell and electrolyzer is platinum and/or its derivatives. The use of metal free graphene based heteroatom doped ORR catalyst may be a promising alternative for conventional platinum electrocatalyst. In particular, nitrogen-doped Graphene synthesized from natural carbon based biomass material has the potential to be a sustainable, green and economical ORR. In this study, Assam silk cocoons was used to synthesize nitrogen doped graphene based catalyst via one step in-situ pyrolysis. The morphological and chemical characterization of...
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Papers by Biraj Kumar Kakati