Proton-conducting electrolytes for direct methanol and direct urea fuel cells - A state-of-the-art review

This review focuses on the protonicisuperprotonic electrolytes used for application in direct methanol and direct urea/urine fuel cells. Since, methanol has. high energy density, which is essential for portable direct methanol fuel cells, and is simpler to store and transport than conventional hydrogen as fuel. However, methanol is not readily available, which makes waste an attractive option as a fuel source, resulting in the development of direct urea fuel cells. Fuel cells that use waste that contains hydrogen, like waste water or urine, are attractive because of their potential to generate energy from low-cost, abundant sources

Young coconut juice can accelerate the healing process of cutaneous wounds

<p>Abstract</p> <p>Background</p> <p>Estrogen has been reported to accelerate cutaneous wound healing. This research studies the effect of young coconut juice (YCJ), presumably containing estrogen-like substances, on cutaneous wound healing in ovairectomized rats.</p> <p>Methods</p> <p>Four groups of female rats (6 in each group) were included in this study. These included sham-operated, ovariectomized (ovx), ovx receiving estradiol benzoate (EB) injections intraperitoneally, and ovx receiving YCJ orally. Two equidistant 1-cm full-thickness skin incisional wounds were made two weeks after ovariectomy. The rats were sacrificed at the end of the third and the fourth week of the study, and their serum estradiol (E2) level was measured by chemiluminescent immunoassay. The skin was excised and examined in histological sections stained with H&E, and immunostained using anti-estrogen receptor (ER-α an ER-β) antibodies.</p> <p>Results</p> <p>Wound healing was accelerated in ovx rats receiving YCJ, as compared to controls. This was associated with significantly higher density of immunostaining for ER-α an ER-β in keratinocytes, fibroblasts, white blood cells, fat cells, sebaceous gland, skeletal muscles, and hair shafts and follicles. This was also associated with thicker epidermis and dermis, but with thinner hypodermis. In addition, the number and size of immunoreactive hair follicles for both ER-α and ER-β were the highest in the ovx+YCJ group, as compared to the ovx+EB group.</p> <p>Conclusions</p> <p>This study demonstrates that YCJ has estrogen-like characteristics, which in turn seem to have beneficial effects on cutaneous wound healing.</p

High conductivity and high density proton conducting Ba1-xSrxCe0.5Zr0.35Y0.1Sm0.05O3-delta (x=0.5, 0.7, 0.9, 1.0) perovskites for IT-SOFC

Solid oxide fuel cell (SOFC) has been achieving attention in term of possibility in variety of fuels. Proton conductor enhanced conventional oxide conducting electrolyte has become more and more interesting particularly in intermediate operating temperature. Combination of doped BaCeO3 and BaZrO3 by doping Sr, Y and Sm was studied as the series of Ba1-xSrxCe0.5Zr0.35Y0.1Sm0.05O3-delta (BSCZYSm) by varying composition x = 0.5, 0.7, 0.9 and 1.0. The X-ray analysis reveals right-shifted peaks due to changing in unit cell volume. The cell parameters and density decreased with increasing Sr content. Rietveld refinement shows that all compositions crystallize in the cubic symmetry in the space group Pm-3m. Thermogravimetric analysis on dried and hydrated samples under nitrogen show significant weight change to prove the proton uptake at higher temperature. Scanning electron microscopy shows that the density is higher than 90% for all samples. BSCZYSm with x = 0.5 shows the highest conductivity in wet argon condition which is 2.391 x 10(-3) S cm(-1) at 700 degrees C. Particle size of materials were examined and reveal average diameter of 5.8 mu m approximately

Structural and electrochemical characterization of BaCe0.7Zr0.2Y0.05Zn0.05O3 as an electrolyte for SOFC-H

As a potential electrolyte for proton-conducting solid oxide fuel cells (SOFC-Hs) and to get better protonic conductivity and stability, zinc doped BCZY material has been found to be promising. In this study, we report a new composition of proton conductors BaCe0.7Zr0.2Y0.05Zn0.05O3 (BCZYZn5) which was investigated using XRD, SEM and conductivity measurements. Rietveld refinement of the XRD data revel a cubic perovskite structure with Pm-3m space group. BaCe0.7Zr0.2Y0.05Zn0.05O3 shows cell parameter a = 4.3452(9) \uc5. Scanning electron microscopy images shows that the grain sizes are large and compact which gives the sample high density and good protonic conductivity. The total conductivity in wet atmosphere is significantly higher than that of dry condition and the conductivity was found to be 0.276 7 10-3 Scm-1 and 0.204 7 10-3 Scm-1 at 600\ub0C in wet and dry Ar, respectively. This study indicated that perovskite electrolyte BCZYZn5 is a promising material for the next generation intermediate temperature solid oxide fuel cells (IT-SOFCs)

High conductivity and high density proton conducting Ba1-xSrxCe0.5Zr0.35Y0.1Sm0.05O3-delta (x=0.5, 0.7, 0.9, 1.0) perovskites for IT-SOFC

Solid oxide fuel cell (SOFC) has been achieving attention in term of possibility in variety of fuels. Proton conductor enhanced conventional oxide conducting electrolyte has become more and more interesting particularly in intermediate operating temperature. Combination of doped BaCeO3 and BaZrO3 by doping Sr, Y and Sm was studied as the series of Ba1-xSrxCe0.5Zr0.35Y0.1Sm0.05O3-delta (BSCZYSm) by varying composition x = 0.5, 0.7, 0.9 and 1.0. The X-ray analysis reveals right-shifted peaks due to changing in unit cell volume. The cell parameters and density decreased with increasing Sr content. Rietveld refinement shows that all compositions crystallize in the cubic symmetry in the space group Pm-3m. Thermogravimetric analysis on dried and hydrated samples under nitrogen show significant weight change to prove the proton uptake at higher temperature. Scanning electron microscopy shows that the density is higher than 90% for all samples. BSCZYSm with x = 0.5 shows the highest conductivity in wet argon condition which is 2.391 x 10(-3) S cm(-1) at 700 degrees C. Particle size of materials were examined and reveal average diameter of 5.8 mu m approximately

Structure-conductivity relationship of PrBaMnMoO6-δ through in-situ measurements: A neutron diffraction study

The structural and electrochemical properties of the double perovskite-type oxide, PrBaMnMoO6-δ, was investigated using neutron diffraction with in-situ conductivity measurement under a dry Argon atmosphere from 25 \ub0C to 700 \ub0C. A Rietveld refinement of the neutron diffraction data confirmed monoclinic symmetry in the P21/n space group. Rietveld refinement also confirms the unit cell parameters of a = 5.6567 (1) \uc5, b = 5.6065 (2) \uc5, c = 7.9344 (1) \uc5 and β = 84.43\ub0 with reliable atomic positions and refinement factors (R-factors). Neutron diffraction data refinement shows two minor phases (&lt;5%), an orthorhombic AB2O5 type phase of PrMn2O5 in the Pbam (No. 32) space group with unit cell parameters, a = 7.9672 (1) \uc5, b = 8.9043 (2) \uc5 and c = 5.8540 (1) \uc5 and a scheelite phase of BaMoO4 in the tetragonal I41/a (88) space group with the unit cell parameters, a = b = 5.9522 (1) \uc5, and c = 12.3211 (2) \uc5. Morphological images revealed a porous and intertwined microstructure. In-situ conductivity measurement shows that the total conductivity of this material was 130.84 Scm−1 at 700 \ub0C

Ceramic fuel cells using novel proton-conducting BaCe0.5Zr0.3Y0.1Yb0.05Zn0.05O3-δ electrolyte

Protonic ceramic fuel cells have become extremely interesting due to their high power output at the intermediate temperature range (400–700\ua0\ub0C). Significant progress has been made to develop electrolyte materials, doped barium cerates-zirconate, which gets the leading role due to its high chemical stability and high ionic conductivity. Here, we present a new composition BaCe0.5Zr0.3Y0.1Yb0.05Zn0.05O3-δ (BCZYYbZn05), where addition of 5\ua0mol% Zn with Ce, Zr, Y, and Yb at the B-site of the perovskite material shows high stability with high conductivity. The material was synthesized by solid-state reaction route at 1400\ua0\ub0C which showed 98% relative density. Rietveld analysis of neutron powder diffraction data reveal an orthorhombic structure with Pbnm space group. Thermogravimetric analysis shows about 1.06% weight loss from 200 to 1000\ua0\ub0C which is mainly related to the formation of the oxygen vacancies. In wet hydrogen atmosphere, this material shows higher conductivity and lower activation energy than dry hydrogen atmosphere indicates the conduction type as protonic conduction. The anode-supported single test cell based on this electrolyte material demonstrates peak power densities 649 mW cm−2 at 700\ua0\ub0C using conventional BSCF cathode, representing an important step toward commercially viable SOFC technology