Characterization of Chloroclosoborane Acids as Electrolytes for Acid Fuel Cells

Abstract

The perchloroclosoborane acids, H2B12Cl12 and H2B10Cl10 , were prepared in high purity and investigated as alternative electrolytes to H3PO4 in moderate temperature acid fuel cells. Procedures were developed for the purification of the acids prepared from commercially available salts. The purified acids were characterized by infrared, electronic, NMR, and mass spectroscopy. Concentrated aqueous solutions of the acids were found to have low ionic conductivity and a moderate water vapor pressure. The mono anions, B12Cl12− and B10Cl10− , formed from reactions of concentrated aqueous solutions or the solid hydrates of the acids. The B12Cl122− and B10Cl102− anions were also found to adsorb on electrocatalytic Pt surfaces.

Halogenated Sodium-closo-Dodecaboranes as Solid-State Ion Conductors

“…22 Acids of perchlorocloso-boranes, H 2 B 10 Cl 10 and H 2 B 12 Cl 12 , were also studied to potentially replace H 3 PO 4 electrolytes in acidic fuel cells, but were found to have modest decomposition temperatures (< 200 °C). 24 While many electrochemical studies require electrolytes to be used at ambient temperature, some technologies require higher operating temperatures. The sodiumsulphur battery (NaS) is comprised of a molten sodium anode and a molten sulphur cathode that are separated by a ceramic, Na-conducting β-Al 2 O 3 electrolyte.…”

Oxidation of closo‐[B12Cl12]2− to the Radical Anion [B12Cl12].− and to Neutral B12Cl12

“…Whereas the parent cluster [B 12 [3]Alkoxy-substituted ions [B 12 (OR) 12 ] 2À are oxidized at an even lower potential and even neutral B 12 (OR) 12 could be prepared.[4] Very recently, the perhydroxylated radical [B 12 (OH) 12 ]C À has been prepared and structurally characterized.[5] Smaller perhalogenated polyborane cluster radical anions [B n X n ]C À (X = H, Cl, Br, I; n = 6, 8-10), which are derived by one-electron oxidation from the corresponding closo clusters have been prepared and characterized by chemical and electrochemical methods. [6] Halogen substitution and an increasing cluster size significantly increase the resistance to oxidation and consequently the perhalogenated dodecaborates [B 12 X 12 ] 2À (X = halogen) are much more difficult to oxidize.…”

Oxidation von closo‐[B12Cl12]2− zum Radikalanion [B12Cl12].− und zum neutralen B12Cl12

“…[1] Das ikosaedrische closo-Dodecaboration [B 12 12 Me 12 ]C À . [3] Das Oxidationspotential alkoxysubstituierter Cluster [B 12 (OR) 12 ] 2À ist noch niedriger, und sogar die Neutralverbindungen B 12 (OR) 12 konnten synthetisiert werden. [4] Vor kurzem wurde über die Synthese und Charakterisierung des Perhydroxyradikals [B 12 (OH) 12 ]C À berichtet.…”

“…[3] Das Oxidationspotential alkoxysubstituierter Cluster [B 12 (OR) 12 ] 2À ist noch niedriger, und sogar die Neutralverbindungen B 12 (OR) 12 konnten synthetisiert werden. [4] Vor kurzem wurde über die Synthese und Charakterisierung des Perhydroxyradikals [B 12 (OH) 12 ]C À berichtet. [5] Kleinere perhalogenierte Polyboranradikalanionen [B n X n ]C À (X = H, Cl, Br, I; n = 6, 8-10), die durch Einelektronenoxidation der entsprechenden closo-Cluster entstehen, wurden synthetisiert und elektrochemisch charakterisiert.…”

“…[6] [7] und elektrochemisch untersucht worden. [8] [12] In Zuge unserer Untersuchungen des perchlorierten closo-Dodecaborats [B 12 Cl 12 ] 2À als schwach koordinierendes Dianion [13] haben wir, parallel und unabhängig zu Reed et al, [14] B 12 Cl 12 hat nur n Gerüstelektronenpaare statt der n + 1 Gerüstelektronenpaare, die für eine closo-Struktur nach den Wade-Regeln erwartet werden würden. [21] Solche Elektronenmangelverbindungen werden häufig auch mit dem Ausdruck hypercloso bezeichnet.…”