Anion dependent CO/H₂ production ratio from CO₂ reduction on Au electro-catalyst

Hong, Sujik,Lee, Seunghwa,Kim, Sohaeng,Lee, Jae Kwang,Lee, Jaeyoung Elsevier 2017 CATALYSIS TODAY - Vol.295 No.-

<P><B>Abstract</B></P> <P>In this study, we first demonstrate that CO production selectivity from CO<SUB>2</SUB> on Au electro-catalyst depends on the type of electrolyte anion. Comparing the faradaic efficiencies of H<SUB>2</SUB>, HCOO<SUP>−</SUP> and CO in the presence of different anions such as Cl<SUP>−</SUP>, HPO<SUB>4</SUB> <SUP>2−</SUP>, SO<SUB>4</SUB> <SUP>2−</SUP> and HCO<SUB>3</SUB> <SUP>−</SUP> at constant potential of −0.7V (<I>vs.</I> RHE), we observe that the CO/H<SUB>2</SUB> ratio could be enhanced due to strongly adsorbed anion such as Cl<SUP>−</SUP>. Although HPO<SUB>4</SUB> <SUP>2−</SUP> is more strongly adsorbed than SO<SUB>4</SUB> <SUP>2−</SUP> and HCO<SUB>3</SUB> <SUP>−</SUP> on the surface of electrode, CO<SUB>2</SUB> reduction in HPO<SUB>4</SUB> <SUP>2−</SUP> containing solution exhibited a minimum faradaic efficiency of CO (11%) but a maximum faradaic efficiency of H<SUB>2</SUB> (70%). Based on physicochemical analytical tools (LSV, EIS, SEM, XPS and XRD) and according to previous studies, we conclude that the product distribution is associated with distinct properties caused by characteristic of each anion when adsorbed on the electrode surface such as specific adsorption strength and intrinsic characteristic of anions.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The anion effect of 4 electrolytes for CO<SUB>2</SUB>RR on Au catalyst are investigated. </LI> <LI> The specific adsorption of anions could contribute to suppressing HER. </LI> <LI> Chloride anion plays a notable role as increasing CO/H<SUB>2</SUB> production ratio. </LI> <LI> Phosphate anion contributes to decrease CO/H<SUB>2</SUB> production ratio. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Depending on electrolytes containing different anions, CO/H<SUB>2</SUB> production ratio of CO<SUB>2</SUB> electroreduction on Au catalyst was differently observed. Usually, a specific adsorption strength of anions played a key role in determination of CO/H<SUB>2</SUB> ratio by a suppressing hydrogen evolution reaction. However, unlike that, certain anions such as chloride and phosphate differently contribute to increase CO/H<SUB>2</SUB> ratio due to their intrinsic characteristics.</P> <P>[DISPLAY OMISSION]</P>

Mathematical Models of Competitive Adsorption of Inorganic Anions in Soils

이교석,이동성,이재봉,주리나,이명연,정덕영 한국토양비료학회 2015 한국토양비료학회지 Vol.48 No.6

Competition among anion species in solution for same sorption sites and soil surface can be of major significance in determining the effective mobility of any potentially adsorbing species. Major soil anion species include OH-, F-, Cl-, HCO3-, CO3-, NO3-, SO42-, and PO43-. And some micro nutrients such as boron and molybdenum exist as H2BO3- and MoO42-, as do some heavy metals such as chrome and arsenic as CrO42- and HAsO42-. Pesticides such as 2,4,5-T and 2,4-D also exist as anions. Many anion species are retained by more complex mechanisms than the simple electrostatic attractions involved in most cation adsorption reactions. In binary system composed of two anions, the adsorption of one anion is influenced by the other anion due to the competition for the available and limited binding sites in soil constituents. The specifically adsorbed anions may compete more effectively for sorption sites than that of nonspecifically adsorbed anion. In this study, we aim to evaluate the mathematical models to determine the magnitude of concentration variations in adsorption due to competitive interactions between anions introduced to a system in binary mixtures.

Mathematical Models of Competitive Adsorption of Inorganic Anions in Soils

Lee, Kyo Suk,Lee, Dong Sung,Lee, Jae Bong,Joo, Rhee Na,Lee, Myong Yun,Chung, Doug Young Korean Society of Soil Science and Fertilizer 2015 한국토양비료학회지 Vol.48 No.6

Competition among anion species in solution for same sorption sites and soil surface can be of major significance in determining the effective mobility of any potentially adsorbing species. Major soil anion species include $OH^-$, $F^-$, $Cl^-$, $HCO_3{^-}$, $CO_3{^-}$, $NO_3{^-}$, $SO_4{^{2-}}$, and $PO_4{^{3-}}$. And some micro nutrients such as boron and molybdenum exist as $H_2BO_3{^-}$ and $MoO_4{^{2-}}$, as do some heavy metals such as chrome and arsenic as $CrO_4{^{2-}}$ and $HAsO_4{^{2-}}$. Pesticides such as 2,4,5-T and 2,4-D also exist as anions. Many anion species are retained by more complex mechanisms than the simple electrostatic attractions involved in most cation adsorption reactions. In binary system composed of two anions, the adsorption of one anion is influenced by the other anion due to the competition for the available and limited binding sites in soil constituents. The specifically adsorbed anions may compete more effectively for sorption sites than that of nonspecifically adsorbed anion. In this study, we aim to evaluate the mathematical models to determine the magnitude of concentration variations in adsorption due to competitive interactions between anions introduced to a system in binary mixtures.

Mathematical Models of Competitive Adsorption of Inorganic Anions in Soils

Kyo Suk Lee,Dong Sung Lee,Jae Bong Lee,Rhee Na Joo,Myong Yun Lee,Doug Young Chung 한국토양비료학회 2015 한국토양비료학회지 Vol.48 No.6

Competition among anion species in solution for same sorption sites and soil surface can be of major significance in determining the effective mobility of any potentially adsorbing species. Major soil anion species include OH<SUP>-</SUP>, F<SUP>-</SUP>, Cl<SUP>-</SUP>, HCO₃<SUP>-</SUP>, CO₃<SUP>-</SUP>, NO₃<SUP>-</SUP>, SO₄<SUP>2-</SUP>, and PO₄<SUP>3-</SUP>. And some micro nutrients such as boron and molybdenum exist as H₂BO₃- and MoO₄<SUP>2-</SUP>, as do some heavy metals such as chrome and arsenic as CrO₄<SUP>2-</SUP> and HAsO₄<SUP>2-</SUP>. Pesticides such as 2,4,5-T and 2,4-D also exist as anions. Many anion species are retained by more complex mechanisms than the simple electrostatic attractions involved in most cation adsorption reactions. In binary system composed of two anions, the adsorption of one anion is influenced by the other anion due to the competition for the available and limited binding sites in soil constituents. The specifically adsorbed anions may compete more effectively for sorption sites than that of nonspecifically adsorbed anion. In this study, we aim to evaluate the mathematical models to determine the magnitude of concentration variations in adsorption due to competitive interactions between anions introduced to a system in binary mixtures.

Anion Receptor Based on Cyclic Siloxanes Substituted with Trifluoromethane- Sulfonylamide for Solid Polymer Electrolytes

이원실,우성일,김동욱,이창진,강영구 한국고분자학회 2010 Macromolecular Research Vol.18 No.3

An anion receptor based on cyclic siloxanes substituted with trifluoromethane-sulfonylamide was prepared to enhance the ionic conductivity of the solid polymer electrolytes. The anion receptor contains four anioncomplexing sites at its peripherals and bears a geometry with low steric hindrance, which makes the anions access and bind easily. The anion receptor effectively enhanced the ionic conductivity of the polymer electrolyte containing LiCl by two orders of magnitude and LiCF3SO3 by one order. The experimental results showed that the anion receptors trap the anions in a one-to-one coordination between the anion-complexing site and anion. The highest ionic conductivity was observed at the lowest activation energy, which was estimated from the VTF plot. The anion receptor was found to be electrochemically stable up to 5 V, which is suitable for a lithium polymer battery.

Formation of a novel bio-based elastomer from polybutadiene and epoxidized soybean oil via post-living anionic polymerization

Boonkerd, Kanoktip,Moon, Byeong Kyu,Kim, Min Cheol,Kim, Jin Kuk SAGE Publications 2014 The Journal of elastomers and plastics Vol.46 No.7

<P>The aim of this research was to develop a novel bio-based elastomer, chain-end functionalized polybutadiene (PBD), from epoxidized soybean oil (ESO), to be used as a processing aid for commercial PBD. This material was successfully synthesized in this study via post-living anionic polymerization of poly(butadienyl)lithium and ESO. The <I>gel permeation </I>chromatography revealed that the products had a mixture of molecular weights, comprising roughly three, two, and one times higher than that of the pure PBD. The majority of the molecules in the product had a two-fold higher molecular weight at the peak value (<I>M</I> <SUB>p</SUB>) than the original PBD chain. The result obtained from the reaction of PBD anions with epoxidized methyl oleate indicated that the ester group showed the higher reactivity toward the PBD anion than the epoxide group. Therefore, the formation of bio-based elastomer from the PBD anions and ESO occurred via the nucleophilic substitution of PBD anion with the carbon atom of the ester group with the loss of the leaving group, the alkoxide, and then followed by nucleophilic addition of another PBD anion to the newly formed ketone, yielding an alcoholate anion. The alcoholate anion was then terminated by hydrogen abstraction from methanol, leading to the formation of chain-end epoxidized fatty acid ester functionalized PBD. The ring opening of the epoxide group of the ESO also took place simultaneously, yielding the product with the three-fold higher <I>M</I> <SUB>p</SUB> than the original PBD. However, the ring opening of epoxide group was decreased when the size of the PBD anion and the amount of the ESO in the reaction were increased.</P>

Synergy effect for performance of anionic SDS/ADS mixtures with amphoteric and nonionic surfactants

Hongche Noh,Taeho Kang,Ji Soo Ryu,Si Yeon Kim,Seong-Geun Oh 한국유화학회 2016 한국응용과학기술학회지 Vol.33 No.3

Detergency and surface active properties of mixed anionic surfactants with amphoteric and nonionic were investigated. Sodium dodecyl sulfate (SDS) and ammonium dodecyl sulfate(ADS) as anionic surfactants and cocamidopropyl betaine (CAPB) as an amphoteric surfactant were used. Nonionic surfactants, which are butyl glucoside (BG), octyl glucoside (OG), decyl glucoside(DG), lauryl dimethylamine oxide (AO) and saponin were also used. To study the synergy effects of mixed SDS/ADS anionic surfactant systems, amphoteric and nonionic surfactants were added into the mixed anionic surfactants. Investigated properties of surfactant mixtures were critical micelle concentration (CMC), surface tension (γ), wettability. In addition, based on these properties, detergency of each sample was examined. Surfactant mixtures are anionics (SDS/ADS), anionic/amphoteric/nonionic (SDS/ADS/CAPB/ saponin), and anionic/nonionic (SDS/ADS/BG/saponin, SDS/ADS/OG/saponin, SDS/ADS/ DG/saponin, and SDS/ADS/AO/saponin). With the addition of amphoteric and nonionic to mixed anionic surfactants, CMC and γ were decreased. Addition of CAPB, which is amphoteric, showed the best property at CMC and γ. Furthermore, as the chain length of hydrocarbon in alkyl glucosides was increased, the CMC and γ were enhanced. However, the wettability did not exactly match up with CMC and γ. The surfactant mixture, which contained DG, showed the best performance at wetting time. Detergency was measured at various temperatures (15 oC, 30 oC, 50 oC). The cleaning performance was enhanced by increasing washing temperature. Moreover, detergency was influenced by not only CMC and γ but also wettability. Although CMC and γ were not minimum at surfactant mixture that included DG, the best cleaning performance showed in that sample.

Synergy effect for performance of anionic SDS/ADS mixtures with amphoteric and nonionic surfactants

Noh, Hongche,Kang, Taeho,Ryu, Ji Soo,Kim, Si Yeon,Oh, Seong-Geun The Korean Society of Applied Science and Technolo 2016 한국응용과학기술학회지 Vol.33 No.3

Detergency and surface active properties of mixed anionic surfactants with amphoteric and nonionic were investigated. Sodium dodecyl sulfate (SDS) and ammonium dodecyl sulfate (ADS) as anionic surfactants and cocamidopropyl betaine (CAPB) as an amphoteric surfactant were used. Nonionic surfactants, which are butyl glucoside (BG), octyl glucoside (OG), decyl glucoside (DG), lauryl dimethylamine oxide (AO) and saponin were also used. To study the synergy effects of mixed SDS/ADS anionic surfactant systems, amphoteric and nonionic surfactants were added into the mixed anionic surfactants. Investigated properties of surfactant mixtures were critical micelle concentration (CMC), surface tension (${\gamma}$), wettability. In addition, based on these properties, detergency of each sample was examined. Surfactant mixtures are anionics (SDS/ADS), anionic/amphoteric/nonionic (SDS/ADS/CAPB/saponin), and anionic/nonionic (SDS/ADS/BG/saponin, SDS/ADS/OG/saponin, SDS/ADS/DG/saponin, and SDS/ADS/AO/saponin). With the addition of amphoteric and nonionic to mixed anionic surfactants, CMC and ${\gamma}$ were decreased. Addition of CAPB, which is amphoteric, showed the best property at CMC and ${\gamma}$. Furthermore, as the chain length of hydrocarbon in alkyl glucosides was increased, the CMC and ${\gamma}$ were enhanced. However, the wettability did not exactly match up with CMC and ${\gamma}$. The surfactant mixture, which contained DG, showed the best performance at wetting time. Detergency was measured at various temperatures ($15^{\circ}C$, $30^{\circ}C$, $50^{\circ}C$). The cleaning performance was enhanced by increasing washing temperature. Moreover, detergency was influenced by not only CMC and ${\gamma}$ but also wettability. Although CMC and ${\gamma}$ were not minimum at surfactant mixture that included DG, the best cleaning performance showed in that sample.

Flexibility of Inorganic Tennis Ball Structures Inducing Anion Selectivity

Kim, Ki-Hyun,Park, Jung Su,Kang, Tae Yi,Oh, Kyungeun,Seo, Mi-Sook,Sohn, Youn Soo,Jun, Moo-Jin,Nam, Wonwoo,Kim, Kwan Mook WILEY-VCH Verlag 2006 Chemistry Vol.12 No.27

<P>Inorganic tennis balls (ITBs), [[{Pt(betmp)(dach)}<SUB>2</SUB>Cu]<SUB>2</SUB>(X)][X]<SUB>3</SUB> (in which X=ClO<SUB>4</SUB><SUP>−</SUP> (3), NO<SUB>3</SUB><SUP>−</SUP> (4), Cl<SUP>−</SUP> (5) and Br<SUP>−</SUP> (6); dach=trans-1,2-diaminocyclohexane and betmp=bisethylthiomethylidenepropanedioate) and [[{Pt(dteym)(dach)}<SUB>2</SUB>Cu]<SUB>2</SUB>(PF<SUB>6</SUB>)][PF<SUB>6</SUB>]<SUB>3</SUB> (7; dteym=1,3-dithiepane-2-ylidenemalonate), were prepared as crystals. Investigation of their X-ray crystal structures revealed that shapes of the cavities in ITBs show significant distortions that depend on the properties of the encapsulated anions. The Cu⋅⋅⋅Cu* distance was observed to be longest in 7 and shortest in 5, the difference between them being 2.05 Å. The flexibility of cavity structures of ITBs makes it possible to encapsulate various anions inside the cavity, while their distortions may be a reason for the difference in the encapsulating ability for anions, that is, anion selectivity. Especially, the distortions observed in 7 are so severe that the encapsulating ability of the cavity for PF<SUB>6</SUB><SUP>−</SUP> is very low compared to other anions. The shapes of ITBs with ClO<SUB>4</SUB><SUP>−</SUP> and BF<SUB>4</SUB><SUP>−</SUP> ions inside their cavities are very similar; however, ClO<SUB>4</SUB><SUP>−</SUP> is encapsulated by the cavity better than BF<SUB>4</SUB><SUP>−</SUP>, which is explicable by the difference of metal–anion interactions. This structural study on ITBs gives a clue to the origin of the anion selectivity of the cavity in ITBs previously investigated by <SUP>19</SUP>F NMR spectroscopy of the ITBs in methanol.</P> <B>Graphic Abstract</B> <P>Anions for tennis! Inorganic tennis balls (ITB) have been studied both in solution and the solid state. The cavity in an ITB is flexible and encapsulates various anions selectively. An example is shown here. <img src='wiley_img/09476539-2006-12-27-CHEM200501626-content.gif' alt='wiley_img/09476539-2006-12-27-CHEM200501626-content'> </P>

Transdermal Permeation-enhancing Activities of some Inorganic Anions

Ko, Young-Il,Kim, Sung-Su,Han, Suk-Kyu The Pharmaceutical Society of Korea 1995 Archives of Pharmacal Research Vol.18 No.4

Effects of sodium salts of various monovalent inorganic anions on transdermal permeation of salicylic acid were investigated. In in-vitro experiment using a Franz-type diffusion cell and excisicylic acid were investigated. In-vitro experiment using a Franze-type diffusion cell and excised mouse skin, the permeation-enhancing activities of the sodium salts of inoraganic anions were rougly proportional to lyotropic Hofmeister serlling abilities of the anions l F/sup -/ <So/sub 4//sup 2-/ < Cl/sup -/<ClO/sub 4//sup -/<NP/sub 3//sup -/<SCN/sup -/<Br/sup -/<l/sup -/,i.e. l/sup -/, Br/sup -/ SCN/sup -/ increased the flux of drugs through the mouse skin, while F/sup -/, SO/sub 4//sup 2-/, Cl/sup -/, Clo/sub 4//sup-/ and NO/sub 3//sup -/ decreased or did not affect the flux. In in-vivo experiment using the rabbit as the test animal, the plasma concentration of salicylic acid of the rabbit to which 10%-salicylic acid ointment containing 5%-Nal or NaBr was applied was significantly higher than that of the rabbit to which the ointment without the electrolyes was applied. The amounts of sterol leached out of stratukm comeum sheet when the sheet wsas immersed in aqueous solutions of Nal, NaBr, or NaSCN were much more than that of stratum corneum immersed in aqueous solutions of the other inorganic anions. The FTIR/ATR spectroscopy showed that the peaks at 2853 cm/sup -1/ and 2924 cm/sup -1/ in the IR absorption spectrum of the stratum comeum heet of the mouse were shifted to higher frequencies by the anions which enhanced the transdermal drug permeation. while not shifted by the anions which did not have ant permeation-enhancing activities or have permeation-reducing activities. These results suggest that sodium salts of some anions such as iodide, bromide and thiocyanate enhance transdermal permeation of salicylic acid through swelling and perturbation of the skin structure by these anions.