583-52-8Relevant articles and documents
Ethylene glycol, 2-propanol electrooxidation in alkaline medium on the ordered intermetallic PtPb surface
Feng, Yanyan,Yin, Wenping,Li, Zhi,Huang, Chengde,Wang, Yuxin
, p. 6991 - 6999 (2010)
The ethylene glycol and 2-propanol electrooxidation reaction was studied on carbon dispersed ordered intermetallic PtPb nanocatalysts in KOH solution. X-ray diffraction and X-ray photoelectron spectroscopy were used to characterize ordered intermetallic PtPb/C catalysts. The electrochemical behaviors for the ethylene glycol and 2-propanol electrooxidation reaction were measured in a thin film electrode by cyclic voltammetry, Tafel curves and electrochemical impedance spectroscopy. The results showed that in contrast with PtRu/C and Pt/C catalyst, ordered intermetallic PtPb/C had better electroactivity, and kinetic mechanism of PtPb/C is complex. Although the activity of electrocatalysts depends on many factors, such as modification of geometric and electronic structure by Pt-Pb interaction, crystalline size and so on. But the key factor for each electrooxidation reaction was different. For ethylene glycol electrooxidation, the effect of formation and desorption of poisonous species on activity of catalyst was very significant. For 2-propanol electrooxidation, the modification of geometric and electronic structures may be play a decisive role in the enhance activity of electrocatalyst.
Margulies, R.
, (1894)
Countercations and Solvent Influence CO2 Reduction to Oxalate by Chalcogen-Bridged Tricopper Cyclophanates
Cook, Brian J.,Di Francesco, Gianna N.,Abboud, Khalil A.,Murray, Leslie J.
, p. 5696 - 5700 (2018)
One-electron reduction of Cu3EL (L3- = tris(β-diketiminate)cyclophane, and E = S, Se) affords [Cu3EL]-, which reacts with CO2 to yield exclusively C2O42- (95% yield, TON = 24) and regenerate Cu3EL. Stopped-flow UV/visible data support an A→B mechanism under pseudo-first-order conditions (kobs, 298K = 115(2) s-1), which is 106 larger than those for reported copper complexes. The kobs values are dependent on the countercation and solvent (e.g., kobs is greater for [K(18-crown-6)]+ vs (Ph3P)2N+, and there is a 20-fold decrease in kobs in THF vs DMF). Our results suggest a mechanism in which cations and solvent influence the stability of the transition state.
Recognition of dicarboxylate anions by a ditopic hexaazamacrocycle containing bis-p-xylyl spacers
Carvalho, Silvia,Delgado, Rita,Fonseca, Nelson,Felix, Vitor
, p. 247 - 257 (2006)
The hexaprotonated form of the hexaazamacrocycle, 7,22-dimethyl-3,7,11,18, 22,26-hexaazatricyclo[26.2.2.2.13.16]tetratriaconta-1(30),13,15,28,31, 33-hexaene, (H6Me2[30]pbz2N6) 6+, was used as a receptor for the molecular recognition of aliphatic and aromatic carboxylate substrates. The receptor-substrate binding behaviour of (H6Me2[30]pbz2N6)6+ with aliphatic > -O2C(CH2) nCO2-, n = 0 to 4] and aromatic (benzoate, phthalate, isophthalate, and terephthalate) substrates was evaluated by potentiometry and 1H NMR spectroscopy. The association constants of the entities formed were determined in H2O at 298.0 K and 0.1 M KNO3 (by potentiometry) and in D2O (by 1H NMR). The constants for the aliphatic substrates are much lower than for the aromatic ones. NMR spectroscopy allowed the conclusion that the recognition process might involve H-bonding, electrostatic and π-π stacking interactions, the strength and the type of them depending on the substrate. The cooperative conjugation of the three types of interactions only occurs when terephthalate is the substrate. Molecular dynamics simulations (MD) in a periodic box of water solvent molecules were also used to investigate the nature of the binding association between the receptor and the three aromatic dicarboxylate anions (phthalate, isophthalate, and terephthalate). These studies confirmed that the (H6Me2[30]pbz2N6)6+ receptor encapsulates the terephthalate anion with the formation of an inclusion supermolecule stabilized by multiple N-H...O hydrogen bonding and π-π interactions. The molecular recognition between the receptor and the other two aromatic anions, phthalate and isophthalate, also occurs via N-H...O hydrogen bonds, but outside of the macrocyclic cavity. The results are discussed in terms of energetic and entropie contributions and showed that the binding association between the receptor and these anions is favourable. the Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2006.
Electrooxidation of ethylene glycol and glycerol on Pd-(Ni-Zn)/C anodes in direct alcohol fuel cells
Marchionni, Andrea,Bevilacqua, Manuela,Bianchini, Claudio,Chen, Yan-Xin,Filippi, Jonathan,Fornasiero, Paolo,Lavacchi, Alessandro,Miller, Hamish,Wang, Lianqin,Vizza, Francesco
, p. 518 - 528 (2013/06/05)
The electrooxidation of ethylene glycol (EG) and glycerol (G) has been studied: in alkaline media, in passive as well as active direct ethylene glycol fuel cells (DEGFCs), and in direct glycerol fuel cells (DGFCs) containing Pd-(Ni-Zn)/C as an anode electrocatalyst, that is, Pd nanoparticles supported on a Ni-Zn phase. For comparison, an anode electrocatalyst containing Pd nanoparticles (Pd/C) has been also investigated. The oxidation of EG and G has primarily been investigated in half cells. The results obtained have highlighted the excellent electrocatalytic activity of Pd-(Ni-Zn)/C in terms of peak current density, which is as high as 3300A g(Pd)-1 for EG and 2150A g(Pd)-1 for G. Membrane-electrode assemblies (MEA) have been fabricated using Pd-(Ni-Zn)/C anodes, proprietary Fe-Co/C cathodes, and Tokuyama A-201 anion-exchange membranes. The MEA performance has been evaluated in either passive or active cells fed with aqueous solutions of 5wt % EG and 5wt % G. In view of the peak-power densities obtained in the temperature range from 20 to 80 °C, at Pd loadings as low as 1mg cm -2 at the anode, these results show that Pd-(Ni-Zn)/C can be classified amongst the best performing electrocatalysts ever reported for EG and G oxidation. Copyright
