Name: extending the lifespan of soluble lead flow batteries with a sodium acetate additive
Uploaded: 2019-01-07T14:00:00
Description: Watch this Scientific Journal Video about Extending the Lifespan of Soluble Lead Flow Batteries with a Sodium Acetate Additive at JoVE.com

This work was supported by the Ministry of Science and Technology, R.O.C., under the funding number of NSC 102-2221-E-002-146-, MOST 103-2221-E-002-233-, and MOST 104-2628-E-002-016-MY3.

1. Construction of a SLFB Beaker Cell with a Sodium Acetate Additive
NOTE: This section describes the procedure to construct a SLFB beaker cell with an additive for long-term cycling experiment. The protocol includes the electrolyte preparation with and without additive, electrode pretreatment, cell assembly, and efficiency calculations.
<ol>
	<li>Preparation of lead methanesulfonate (1 L, 1 M as an example)
	<ol>
		<li>In the fume hood, add 274.6 g of methanesulfonic acid (...

<ol>
	<li>Soloveichik, G. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Flow+batteries:+current+status+&amp;+trends.">Flow batteries: current status &amp; trends.</a> Chemical Reviews. 115 (20), 11533-11558 (2015).</li><li>Ravikumar, M. K., Rathod, S., Jaiswal, N., Patil, S., Shukla, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+renaissance+in+redox+flow+batteries.">The renaissance in redox flow batteries.</a> Journal of Solid State Electrochemistry. 21 (9), 2467-2488 (2017).</li><li>Hazza, A., Pletcher, D., Wills, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+novel+flow+battery:+A+lead+acid+battery+based+on+an+electrolyte+with+soluble+lead+(II)+Part+I.+Preliminary+studies.">A novel flow battery: A lead acid battery based on an electrolyte with soluble lead (II) Part I. Preliminary studies.</a> Physical Chemistry Chemical Physics. 6 (8), 1773-1778 (2004).</li><li>Pletcher, D., Wills, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+novel+flow+battery:+A+lead+acid+battery+based+on+an+electrolyte+with+soluble+lead+(II)+Part+II.+Flow+cell+studies.">A novel flow battery: A lead acid battery based on an electrolyte with soluble lead (II) Part II. Flow cell studies.</a> Physical Chemistry Chemical Physics. 6 (8), 1779-1785 (2004).</li><li>Pletcher, D., Wills, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+novel+flow+battery-a+lead+acid+battery+based+on+an+electrolyte+with+soluble+lead+(II).+III.+The+influence+of+conditions+on+battery+performance.">A novel flow battery-a lead acid battery based on an electrolyte with soluble lead (II). III. The influence of conditions on battery performance.</a> Journal of Power Sources. 149, 96-102 (2005).</li><li>Hazza, A., Pletcher, D., Wills, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+novel+flow+battery-a+lead+acid+battery+based+on+an+electrolyte+with+soluble+lead+(II).+IV.+The+influence+of+additives.">A novel flow battery-a lead acid battery based on an electrolyte with soluble lead (II). IV. The influence of additives.</a> Journal of Power Sources. 149, 103-111 (2005).</li><li>Pletcher, D., Zhou, H., Kear, G., Low, C. T. J., Walsh, F. C., Wills, R. G. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+novel+flow+battery-A+lead-acid+battery+based+on+an+electrolyte+with+soluble+lead+(II).+V.+Studies+of+the+lead+negative+electrode.">A novel flow battery-A lead-acid battery based on an electrolyte with soluble lead (II). V. Studies of the lead negative electrode.</a> Journal of Power Sources. 180 (1), 621-629 (2008).</li><li>Pletcher, D., Zhou, H., Kear, G., Low, C. T. J., Walsh, F. C., Wills, R. G. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+novel+flow+battery-A+lead-acid+battery+based+on+an+electrolyte+with+soluble+lead+(II).+Part+VI.+Studies+of+the+lead+dioxide+positive+electrode.">A novel flow battery-A lead-acid battery based on an electrolyte with soluble lead (II). Part VI. Studies of the lead dioxide positive electrode.</a> Journal of Power Sources. 180 (1), 630-634 (2008).</li><li>Li, X., Pletcher, D., Walsh, F. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+novel+flow+battery:+a+lead+acid+battery+based+on+an+electrolyte+with+soluble+lead+(II).+Part+VII.+Further+studies+of+the+lead+dioxide+positive+electrode.">A novel flow battery: a lead acid battery based on an electrolyte with soluble lead (II). Part VII. Further studies of the lead dioxide positive electrode.</a> Electrochimica Acta. 54 (20), 4688-4695 (2009).</li><li>Krishna, M., Fraser, E. J., Wills, R. G. A., Walsh, F. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Developments+in+soluble+lead+flow+batteries+and+remaining+challenges:+An+illustrated+review.">Developments in soluble lead flow batteries and remaining challenges: An illustrated review.</a> Journal of Energy Storage. 15, 69-90 (2018).</li><li>Lin, Y. -. T., Tan, H. -. L., Lee, C. -. Y., Chen, H. -. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stabilizing+the+electrodeposit-electrolyte+interphase+in+soluble+lead+flow+batteries+with+ethanoate+additive.">Stabilizing the electrodeposit-electrolyte interphase in soluble lead flow batteries with ethanoate additive.</a> Electrochimica Acta. 263, 60-67 (2018).</li><li>Oury, A., Kirchev, A., Bultel, Y., Chainet, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=PbO2/Pb2++cycling+in+methanesulfonic+acid+and+mechanisms+associated+for+soluble+lead-acid+flow+battery+applications.">PbO2/Pb2+ cycling in methanesulfonic acid and mechanisms associated for soluble lead-acid flow battery applications.</a> Electrochimica Acta. 71, 140-149 (2012).</li><li>Oury, A., Kirchev, A., Bultel, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Potential+response+of+lead+dioxide/Lead+(II)+galvanostatic+cycling+in+methanesulfonic+acid:+a+morphologico-kinetics+interpretation.">Potential response of lead dioxide/Lead (II) galvanostatic cycling in methanesulfonic acid: a morphologico-kinetics interpretation.</a> Journal of The Electrochemical Society. 160 (1), A148-A154 (2013).</li></ol>

This paper describes an economical method to extend the cycle life of SLFBs: by employing NaOAc agent as an electrolyte additive. A batch of fresh graphite electrodes and nickel plates are preprocessed as aforementioned in Step 1 before long-term cycling experiments. Because inconsistency among commercial carbon electrodes may cause performance deviation of the SLFBs, the physical/chemical pretreatment in Step 1.4 is critical to remove surface residues. The second part of Step 1.4 is employing electrochemical methods to ...

Renewable energy sources including solar and wind have been developed for decades, but their intermittent nature poses great challenges. For a future power grid with renewable energy sources incorporated, grid stabilization and load leveling are critical and can be achieved by integrating energy storage. Redox flow batteries (RFBs) are one of the promising options for grid-scale energy storage. Traditional RFBs contain ion-selective membranes separating anolyte and catholyte; for example, the all-vanadium RFB has shown to operate with high efficiency and a long cycle life1,2. However, their market share as energy storage is very limited in part due to the expensive comprising materials and ineffective ion-selective membranes. On the other hand, a single-flow soluble lead flow battery (SLFB) is presented by Plectcher et al.1,2,3,4,5. The SLFB is membrane-less because it has only one active species, Pb(II) ions. Pb(II) ions are electroplated at the positive electrode as PbO2 and the negative electrode as Pb simultaneously during charging, and convert back to Pb(II) during discharging. A SLFB thus needs one circulation pump and one electrolyte storage tank only, which in turn can potentially lead to reduced capital and operational cost compared to conventional RFBs. The published cycle life of SLFBs, however, is so far limited to less than 200 cycles under normal flow conditions6,7,8,9,10.
Factors leading to a short SLFB cycle life is preliminarily associated with deposition/dissolution of PbO2 at the positive electrode. During charge/discharge processes, the electrolyte acidity is found to increase over deep or repeated cycles11, and protons are suggested to induce the generation of a passivation layer of non-stoichiometric PbOx12,13. The shedding of PbO2 is another phenomenon related to SLFB degradation. Shed PbO2 particles are irreversible and can no longer be utilized. The coulombic efficiency (CE) of SLFBs consequentially declines because of imbalanced electrochemical reactions as well as accumulated electrodeposits at both electrodes. To extend cycle life of SLFBs, stabilizing the pH fluctuation and electrodeposit structure are critical. A recent paper demonstrates an enhanced performance and extended cycle life of SLFBs with addition of sodium acetate (NaOAc) in methanesulfonic electrolyte11.
Here, a detailed protocol for employing NaOAc as an additive to the methanesulfonic electrolyte in SLFBs is described. The SLFB performance is shown to be enhanced and the lifespan can be extended by over 50% in comparison to SLFBs without NaOAc additives. In addition, procedures for throwing index (TI) measurement are illustrated for the purpose of quantitative comparison of additive effects on electrodeposition. Finally, a scanning electron microscopy (SEM) sample preparation method for electrodeposit on SLFB electrodes is described and the additive impact on electrodeposit is manifested in acquired images.

<table>
	<tbody>
		<tr>
			<td>70 mm cellulose filter paper</td>
			<td>Advance</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Autolab</td>
			<td>Metrohm</td>
			<td>PGSTA302N</td>
			<td></td>
		</tr>
		<tr>
			<td>BT-Lab</td>
			<td>BioLogic</td>
			<td>BCS-810</td>
			<td></td>
		</tr>
		<tr>
			<td>commercial carbon composite electrode</td>
			<td>Homy Tech,Taiwan</td>
			<td></td>
			<td>Density 1.75 g cm-3, and electrical conductivity 330 S cm-1</td>
		</tr>
		<tr>
			<td>Diamond saw</td>
			<td>Buehler</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Hydrochloric Acid</td>
			<td>SHOWA</td>
			<td>0812-0150-000-69SW</td>
			<td>35%</td>
		</tr>
		<tr>
			<td>Lead (II) Oxide</td>
			<td>SHOWA</td>
			<td>1209-0250-000-23SW</td>
			<td>98%</td>
		</tr>
		<tr>
			<td>Lutropur MSA</td>
			<td>BASF</td>
			<td>50707525</td>
			<td>70%</td>
		</tr>
		<tr>
			<td>nickel plate</td>
			<td>Lien Hung Alloy Trading Co., LTD., Taiwan,&#160;</td>
			<td></td>
			<td>99%</td>
		</tr>
		<tr>
			<td>Potassium Nitrate</td>
			<td>Scharlab</td>
			<td>28703-95</td>
			<td>99%</td>
		</tr>
		<tr>
			<td>Scanning electron microscopy</td>
			<td>JEOL</td>
			<td>JSM-7800F</td>
			<td>at accelerating voltage of 15 kV</td>
		</tr>
		<tr>
			<td>Sodium Acetate</td>
			<td>SHOWA</td>
			<td>1922-5250-000-23SW</td>
			<td>98%</td>
		</tr>
		<tr>
			<td>water purification system</td>
			<td>Barnstead MicroPure</td>
			<td></td>
			<td>&#160;18.2 M&#937;&#160;&#8226; cm</td>
		</tr>
	</tbody>
</table>

extending the lifespan of soluble lead flow batteries with a sodium acetate additive

In this report, we present a method for the construction of a soluble lead flow battery (SLFB) with an extended cycle life. By supplying an adequate amount of sodium acetate (NaOAc) to the electrolyte, a cycle life extension of over 50% is demonstrated for SLFBs via long-term galvanostatic charge/discharge experiments. A higher quality of the PbO2 electrodeposit at the positive electrode is quantitatively validated for NaOAc-added electrolyte by throwing index (TI) measurements. Images acquired by scanning electron microscopy (SEM) also exhibit more integrated PbO2 surface morphology when the SLFB is operated with the NaOAc-added electrolyte. This work indicates that electrolyte modification can be a plausible route to economically enable SLFBs for large-scale energy storage.

To extend cycle life of SLFBs, NaOAc is supplied as an electrolyte additive. Cycling performance of SLFBs with and without NaOAc additive are examined in parallel, and results are shown in Figure 3. For easier quantitative comparison of cycle life, we define the &#34;death&#34; of a SLFB as when its CE is lower than 80% under continuous galvanostatic charge/discharge. Figure 3a and 3b show that approximately 50% ...

Watch this Scientific Journal Video about Extending the Lifespan of Soluble Lead Flow Batteries with a Sodium Acetate Additive at JoVE.com

Extending the Lifespan of Soluble Lead Flow Batteries with a Sodium Acetate Additive

A protocol for the construction of a soluble lead flow battery with an extended lifespan, in which sodium acetate is supplied in the methanesulfonic electrolyte as an additive, is presented.

In this report, we present a method for the construction of a soluble lead flow battery (SLFB) with an extended cycle life. By supplying an adequate ...

This method extends the cycle life of soluble lead flow batteries by employing sodium acetate as an electrolyte additive, which is an economical and effective approach. In addition, the beaker cell design used in this method is convenient for studying the effects of the electrolyte additive on single flow redox flow batteries. Demonstrating the procedure will be Yong-Hong Lai, Ho-Wei Chan, and Kai-Rui Pan, two grad students and an undergraduate student from my laboratory.To begin, in a fume hood, pour 274.6 grams of 70%methanesulfonic acid into a beaker, and start stirring it with a stir bar. Add 300 milliliters of deionized water, and continue stirring for one to two minutes to thoroughly mix the solution. Then, add 223.2 grams of 98%lead II oxide to the stirring solution in spatula tip-sized increments.Wait for each portion to dissolve completely before adding the next one. Filter the resulting lead methanesulfonate solution three times. Dilute it to one liter with deionized water, and stir it for two to three hours to obtain a one-molar solution.Next, combine in a beaker 20.595 grams of 70%MSA, 150 milliliters of one-molar lead methanesulfonate, and 1.23 grams of sodium acetate. Dilute the mixture to 300 milliliters with deionized water, and stir it for one to two minutes to make an electrolyte solution with sodium acetate as an additive. Next, polish a bare graphite electrode with P100-grit aluminous sandpaper until no impurities are visible.Rinse the polished electrode with deionized water. Then, add 20.83 grams of 35%hydrochloric acid to 200 milliliters of deionized water, and stir well to obtain a one-molar solution of hydrochloric acid. Soak the graphite electrode in the solution for at least eight hours.Thoroughly rinse the graphite electrode with deionized water, and dry it with a low-lint laboratory wipe. Polish a nickel electrode with P100-grit aluminous sandpaper, rinse it with deionized water, and dry it in the same way. Then, wrap polytetrafluoroethylene tape around one side of each electrode, leaving a portion exposed to be connected to the battery tester.Dissolve 3.03 grams of potassium nitrate in 300 milliliters of deionized water. Immerse the exposed sides of both electrodes in this 0.1-molar potassium nitrate solution. Also, place a reference silver-silver chloride electrode in the solution.Then, connect the electrodes to a potentiostat. The graphite working electrode will be the positive electrode, and the nickel counter electrode will be the negative electrode. Apply a potential of 1.80 volts versus silver-silver chloride to the positive electrode for five minutes.Then, apply a potential of negative one volt versus silver-silver chloride to the positive electrode for two minutes to finish the pretreatment. Rinse and dry the electrodes afterwards. Then, connect the pretreated electrodes to a custom electrode positioning board.Place the positioning board on a beaker equipped with a stir bar, and fill the beaker with electrolyte until the solution reaches the appropriate level. Place the beaker assembly on a stirring hot plate, and connect a battery tester to the electrodes. Cover the beaker cell with plastic wrap to prevent evaporation before performing the battery test.Stir the mixture at about 200 rpm during the test. To start the throwing index measurement procedure, weigh two positive electrodes and record their masses. Place a negative electrode in the center position of a Haring-Blum cell apparatus.Place one positive electrode in the assembly near the negative electrode. Place the other positive electrode at a distance several times greater than the distance between the first positive electrode and the negative electrode. Immerse the electrode in the electrolyte of interest, and connect them to a battery tester.Start the test by charging the battery assembly with a constant current density of 20 milliamperes per square centimeter for 30 minutes. After performing the desired charge-discharge cycles, rinse the positive electrodes with deionized water and allow them to dry in ambient air overnight. Then, weigh the positive electrodes, and calculate the amount of metal plated on each electrode.Repeat this process at various linear distance ratios, and generate a throwing index diagram. To prepare an electroplated graphite electrode for SEM, first rinse it with deionized water and allow it to dry at room temperature. Then, use a diamond saw to carefully slice the electrode into samples of the desired size.Cold-mount an electrode sample, fix it in a polisher, and mechanically polish it with 14-eight-and three-millimeter silicon carbide sandpaper in sequence. Rinse the sample with deionized water, and dry it with nitrogen gas after each polishing. Then, polish the sample with a one-millimeter diamond suspension, followed by a slurry of 0.05-millimeter alumina in deionized water.After that, deposit a layer of platinum on the polished sample, and attach it to the sample platform with copper tape. Acquire SEM images of the electroplated material. Adding sodium acetate to the SLFB electrode extended the charge-discharge cycle lifetime by about 50%Adding sodium acetate also improved the throwing characteristics at the positive electrodes, as indicated by the shallower slope in a throwing index diagram.Sodium acetate had no significant effect on the plating behavior at the negative electrode. SEM images of positive electrodes electroplated with lead IV oxide in electrolyte with and without sodium acetate showed that the additive corresponded to a smoother lead IV oxide surface with fewer defects. Impurities are detrimental to the performance of SLFBs.Make sure that lead oxide is completely dissolved in the MSA, and filter out all residual solids before using the electrolyte. Once the plated electrode sample is harvested, other material scalarization techniques such as EBSD, nanoindentation, or x-ray diffraction can be performed to gain insight into the additive's effect on electrodeposition. Remember to prepare the electrolyte in a fume hood because the gas released during this procedure can be hazardous.

extending-lifespan-soluble-lead-flow-batteries-with-sodium-acetate

Research

JoVE Journal

Chemistry

Exploring the Radical Nature of a Carbon Surface by Electron Paramagnetic Resonance and a Calibrated Gas Flow

While the first Electron Paramagnetic Resonance (EPR) studies regarding the effects of oxidation on the structure and stability of carbon radicals date back to the early 1980s the focus of these early papers primarily characterized the changes to the structures under extremely harsh conditions (pH or temperature)1-3. It is also known that paramagnetic molecular oxygen undergoes a Heisenberg spin exchange interaction with stable radicals that extremely broadens the EPR signal4-6. Recently, we reported interesting results where this interaction of molecular oxygen with a certain part of the existing stable radical structure can be reversibly affected simply by flowing a diamagnetic gas through the carbon samples at STP7. As flows of He, CO2, and N2 had a similar effect these interactions occur at the surface area of the macropore system.
This manuscript highlights the experimental techniques, work-up, and analysis towards affecting the existing stable radical nature in the carbon structures. It is hoped that it will help towards further development and understanding of these interactions in the community at large.

Stable radicals that are present in carbon substrates interact with paramagnetic oxygen through a Heisenberg spin exchange. This interaction can be significantly reduced under STP conditions by flowing a diamagnetic gas over the carbon system. This manuscript describes a simple method to characterize the nature of those radicals.

While the first Electron Paramagnetic Resonance (EPR) studies regarding the effects of oxidation on the structure and stability of carbon radicals date ...

Real-time Monitoring of Reactions Performed Using Continuous-flow Processing: The Preparation of 3-Acetylcoumarin as an Example

By using inline monitoring, it is possible to optimize reactions performed using continuous-flow processing in a simple and rapid way. It is also possible to ensure consistent product quality over time using this technique. We here show how to interface a commercially available flow unit with a Raman spectrometer. The Raman flow cell is placed after the back-pressure regulator, meaning that it can be operated at atmospheric pressure. In addition, the fact that the product stream passes through a length of tubing before entering the flow cell means that the material is at RT. It is important that the spectra are acquired under isothermal conditions since Raman signal intensity is temperature dependent. Having assembled the apparatus, we then show how to monitor a chemical reaction, the piperidine-catalyzed synthesis of 3-acetylcoumarin from salicylaldehyde and ethyl acetoacetate being used as an example. The reaction can be performed over a range of flow rates and temperatures, the in-situ monitoring tool being used to optimize conditions simply and easily.

Real-time monitoring allows for fast optimization of reactions performed using continuous-flow processing. Here the preparation of 3-acetylcoumarin is used as an example. The apparatus for performing in-situ Raman monitoring is described, as are the steps required to optimize the reaction.

By using inline monitoring, it is possible to optimize reactions performed using continuous-flow processing in a simple and rapid way. It is also possible ...

Water in Oil Emulsions: A New System for Assembling Water-soluble Chlorophyll-binding Proteins with Hydrophobic Pigments

Chlorophylls (Chls) and bacteriochlorophylls (BChls) are the primary cofactors that carry out photosynthetic light harvesting and electron transport. Their functionality critically depends on their specific organization within large and elaborate multisubunit transmembrane protein complexes. In order to understand at the molecular level how these complexes facilitate solar energy conversion, it is essential to understand protein-pigment, and pigment-pigment interactions, and their effect on excited dynamics. One way of gaining such understanding is by constructing and studying complexes of Chls with simple water-soluble recombinant proteins. However, incorporating the lipophilic Chls and BChls into water-soluble proteins is difficult. Moreover, there is no general method, which could be used for assembly of water-soluble proteins with hydrophobic pigments. Here, we demonstrate a simple and high throughput system based on water-in-oil emulsions, which enables assembly of water-soluble proteins with hydrophobic Chls. The new method was validated by assembling recombinant versions of the water-soluble chlorophyll binding protein of Brassicaceae plants (WSCP) with Chl a. We demonstrate the successful assembly of Chl a using crude lysates of WSCP expressing E. coli cell, which may be used for developing a genetic screen system for novel water-soluble Chl-binding proteins, and for studies of Chl-protein interactions and assembly processes.

This manuscript describes a simple and high-throughput method for assembling water-soluble proteins with hydrophobic pigments that is based on water-in-oil emulsions. We demonstrate the effectiveness of the method in the assembly of native chlorophylls with four variants of recombinant water-soluble-chlorophyll binding proteins (WSCPs) of Brassica plants expressed in E. coli.

Chlorophylls (Chls) and bacteriochlorophylls (BChls) are the primary cofactors that carry out photosynthetic light harvesting and electron transport. ...

Visualization of Ambient Mass Spectrometry with the Use of Schlieren Photography

This manuscript outlines how to visualize mass spectrometry ambient ionization sources using schlieren photography. In order to properly optimize the mass spectrometer, it is necessary to characterize and understand the physical principles of the source. Most commercial ambient ionization sources utilize jets of nitrogen, helium, or atmospheric air to facilitate the ionization of the analyte. As a consequence, schlieren photography can be used to visualize the gas streams by exploiting the differences in refractive index between the streams and ambient air for visualization in real time. The basic setup requires a camera, mirror, flashlight, and razor blade. When properly configured, a real time image of the source is observed by watching its reflection. This allows for insight into the mechanism of action in the source, and pathways to its optimization can be elucidated. Light is shed on an otherwise invisible situation.

This paper presents a protocol for the visualization of gaseous streams of an ambient ionization source using schlieren photography and mass spectrometry.

This manuscript outlines how to visualize mass spectrometry ambient ionization sources using schlieren photography. In order to properly optimize the mass ...

Sulfate Separation by Selective Crystallization with a Bis-iminoguanidinium Ligand

A simple and effective method for selective sulfate separation from aqueous solutions by crystallization with a bis-guanidinium ligand, 1,4-benzene-bis(iminoguanidinium) (BBIG), is demonstrated. The ligand is synthesized as the chloride salt (BBIG-Cl) by in situ imine condensation of terephthalaldehyde with aminoguanidinium chloride in water, followed by crystallization as the sulfate salt (BBIG-SO4). Alternatively, BBIG-Cl is synthesized ex situ in larger scale from ethanol. The sulfate separation ability of the BBIG ligand is demonstrated by selective and quantitative crystallization of sulfate from seawater. The ligand can be recycled by neutralization of BBIG-SO4 with aqueous NaOH and crystallization of the neutral bis-iminoguanidine, which can be converted back into BBIG-Cl with aqueous HCl and reused in another separation cycle. Finally, 35S-labeled sulfate and &#946; liquid scintillation counting are employed for monitoring the sulfate concentration in solution. Overall, this protocol will instruct the user in the necessary skills to synthesize a ligand, employ it in the selective crystallization of sulfate from aqueous solutions, and quantify the separation efficiency.

A protocol for in situ aqueous synthesis of a bis(iminoguanidinium) ligand and its utilization in selective separation of sulfate is presented.

A simple and effective method for selective sulfate separation from aqueous solutions by crystallization with a bis-guanidinium ligand, ...

Synthesis of a Water-soluble Metal&#8211;Organic Complex Array

We demonstrate a method for the synthesis of a water-soluble multimetallic peptidic array containing a predetermined sequence of metal centers such as Ru(II), Pt(II), and Rh(III). The compound, named as a water-soluble metal-organic complex array (WSMOCA), is obtained through 1) the conventional solution-chemistry-based preparation of the corresponding metal complex monomers having a 9-fluorenylmethyloxycarbonyl (Fmoc)-protected amino acid moiety and 2) their sequential coupling together with other water-soluble organic building units on the surface-functionalized polymeric resin by following the procedures originally developed for the solid-phase synthesis of polypeptides, with proper modifications. Traces of reactions determined by mass spectrometric analysis at the representative coupling steps in stage 2 confirm the selective construction of a predetermined sequence of metal centers along with the peptide backbone. The WSMOCA cleaved from the resin at the end of stage 2 has a certain level of solubility in aqueous media dependent on the pH value and/or salt content, which is useful for the purification of the compound.

A potential general method for the synthesis of water-soluble multimetallic peptidic arrays containing a predetermined sequence of metal centers is presented.

We demonstrate a method for the synthesis of a water-soluble multimetallic peptidic array containing a predetermined sequence of metal centers such as ...

Facile Preparation of (2Z,4E)-Dienamides by the Olefination of Electron-deficient Alkenes with Allyl Acetate

Direct cross-coupling between two alkenes via vinylic C-H bond activation represents an efficient strategy for the synthesis of butadienes with high atomic and step economy. However, this functionality-directed cross-coupling reaction has not been developed, as there are still limited directing groups in practical use. In particular, a stoichiometric amount of oxidant is usually required, producing a large amount of waste. Due to our interest in novel 1,3-butadiene synthesis, we describe the ruthenium-catalyzed olefination of electron-deficient alkenes using allyl acetate and without external oxidant. The reaction of 2-phenyl acrylamide and allyl acetate was chosen as a model reaction, and the desired diene product was obtained in 80% isolated yield with good stereoselectivity (Z,E/Z,Z = 88:12) under optimal conditions: [Ru(p-cymene) Cl2]2 (3 mol %) and AgSbF6 (20 mol %) in DCE at 110 &#186;C for 16 h. With the optimized catalytic conditions in hand, representative &#945;- and/or &#946;-substituted acrylamides were investigated, and all reacted smoothly, regardless of aliphatic or aromatic groups. Also, differently N-substituted acrylamides have proven to be good substrates. Moreover, we examined the reactivity of different allyl derivatives, suggesting that the chelation of acetate oxygen to the metal is crucial for the catalytic process. Deuterium-labeled experiments were also conducted to investigate the reaction mechanism. Only Z-selective H/D exchanges on acrylamide were observed, indicating a reversible cyclometalation event. In addition, a kinetic isotope effect (KIE) of 3.2 was observed in the intermolecular isotopic study, suggesting that the olefinic C-H metalation step is probably involved in the rate-determining step.

Facile Preparation of 2Z,4E-Dienamides by the Olefination of Electron-deficient Alkenes with Allyl Acetate

The ruthenium-catalyzed olefination of electron-deficient alkenes with allyl acetate is described here. By using aminocarbonyl as a directing group, this external oxidant-free protocol has high efficiency and good stereo- and regioselectivity, opening a novel synthetic route to (Z,E)-butadiene skeletons.

Direct cross-coupling between two alkenes via vinylic C-H bond activation represents an efficient strategy for the synthesis of butadienes with high ...

Continuous Flow Chemistry: Reaction of Diphenyldiazomethane with p-Nitrobenzoic Acid

Continuous flow technology has been identified as instrumental for its environmental and economic advantages leveraging superior mixing, heat transfer and cost savings through the &#34;scaling out&#34; strategy as opposed to the traditional &#34;scaling up&#34;. Herein, we report the reaction of diphenyldiazomethane with p-nitrobenzoic acid in both batch and flow modes. To effectively transfer the reaction from batch to flow mode, it is essential to first conduct the reaction in batch. As a consequence, the reaction of diphenyldiazomethane was first studied in batch as a function of temperature, reaction time, and concentration to obtain kinetic information and process parameters. The glass flow reactor set-up is described and combines two types of reaction modules with &#34;mixing&#34; and &#34;linear&#34; microstructures. Finally, the reaction of diphenyldiazomethane with p-nitrobenzoic acid was successfully conducted in the flow reactor, with up to 95% conversion of the diphenyldiazomethane in 11 min. This proof of concept reaction aims to provide insight for scientists to consider flow technology&#39;s competitiveness, sustainability, and versatility in their research.

Continuous Flow Chemistry: Reaction of Diphenyldiazomethane with p-Nitrobenzoic Acid

Flow chemistry carries environmental and economic advantages by leveraging superior mixing, heat transfer and cost benefits. Herein, we provide a blueprint to transfer chemical processes from batch to flow mode. The reaction of diphenyldiazomethane (DDM) with p-nitrobenzoic acid, conducted in batch and flow, was chosen for proof of concept.

Continuous flow technology has been identified as instrumental for its environmental and economic advantages leveraging superior mixing, heat transfer and ...

Synthesizing Sodium Tungstate and Sodium Molybdate Microcapsules via Bacterial Mineral Excretion

We present a method, the bacterial mineral excretion (BME), for synthesizing two kinds of microcapsules, sodium tungstate and sodium molybdate, and the two metal oxides&#39; corresponding nanoparticles&#8212;the former being as small as 22 nm and the latter 15 nm. We fed two strains of bacteria, Shewanella algae and Pandoraea sp., with various concentrations of tungstate or molybdate ions. The concentrations of tungstate and molybdate were adjusted to make microcapsules of different length-to-diameter ratios. We found that the higher the concentration the smaller the nanoparticles were. The nanoparticles came in with three length-to-diameter ratios: 10:1, 3:1 and 1:1, which were achieved by feeding the bacteria respectively with a low concentration, a medium concentration, and a high concentration. The images of the hollow microcapsules were taken via the scanning electron microsphere (SEM). Their crystal structures were verified by X-ray diffraction (XRD)&#8212;the crystal structure of molybdate microcapsules is Na2MoO4 and that of tungstate microcapsules is Na2WO4 with Na2W2O7. These syntheses all were accomplished under a near ambient condition.

This work presents a protocol for manufacture sodium tungstate and sodium molybdate microcapsules via bacteria and their corresponding nanoparticles.

We present a method, the bacterial mineral excretion (BME), for synthesizing two kinds of microcapsules, sodium tungstate and sodium molybdate, and the ...

Elemental-sensitive Detection of the Chemistry in Batteries through Soft X-ray Absorption Spectroscopy and Resonant Inelastic X-ray Scattering

Energy storage has become more and more a limiting factor of today's sustainable energy applications, including electric vehicles and green electric grid based on volatile solar and wind sources. The pressing demand of developing high-performance electrochemical energy storage solutions, i.e., batteries, relies on both fundamental understanding and practical developments from both the academy and industry. The formidable challenge of developing successful battery technology stems from the different requirements for different energy-storage applications. Energy density, power, stability, safety, and cost parameters all have to be balanced in batteries to meet the requirements of different applications. Therefore, multiple battery technologies based on different materials and mechanisms need to be developed and optimized. Incisive tools that could directly probe the chemical reactions in various battery materials are becoming critical to advance the field beyond its conventional trial-and-error approach. Here, we present detailed protocols for soft X-ray absorption spectroscopy (sXAS), soft X-ray emission spectroscopy (sXES), and resonant inelastic X-ray scattering (RIXS) experiments, which are inherently elemental-sensitive probes of the transition-metal 3d and anion 2p states in battery compounds. We provide the details on the experimental techniques and demonstrations revealing the key chemical states in battery materials through these soft X-ray spectroscopy techniques.

Here, we present a protocol for typical experiments of soft X-ray absorption spectroscopy (sXAS) and resonant inelastic X-ray scattering (RIXS) with applications in battery material studies.

Energy storage has become more and more a limiting factor of today's sustainable energy applications, including electric vehicles and green electric grid ...