Mechanism of electroreduction of 9-anthraldehyde

Abstract

ANDRZEJ LASIA and ABDELHAQ RAMI. 1987. Can. J. Chem. 65, 744 (1987). The electroreduction of 9-anthraldehyde (ANCHO) and 10-methyl-9-anthraldehyde (MeANCHO) has been studied in aprotic solvents. The anion free radicals of both compounds undergo subsequent dimerization reaction with ANCHOT being more reactive than MeANCHO'. The rate constant of the dimerization reaction depends on the solvent and for ANCHO' in HMPA is equal to 2 x lo4 M-I S-I . Using spectroscopic measurements it has been shown that thedimerization takes place at position 10.ANDRZEJ LASIA et ABDELHAQ RAMI. 1987. Can. J. Chem. 65, 744 (1987).L'ClectrorCduction du 9-anthraldkhyde (ANCHO) et du 10-mCthyl-9-anthraldChyde (MeANCHO) a CtC CtudiCe dans les solvants aprotiques. Les anions radicaux de ces composCs se dimCrisent et ANCHOS est beaucoup plus rkactif que MeANCHO'. La constante de vitesse de dimkrisation dCpend du solvant et pour ANCHO' dans le HMPA cette constante Cgale 2 X lo4 M-I s-'. La structure de dimkre a CtC CtudiCe par la spectroscopie rmn et on a trouvC que la dimCrisation a lieu i la position 10.

The investigation of the kinetics and mechanism of hydrogen evolution reaction on tin

“…2b), which are discussed in more detail later. The Tafel slope at high negative potentials is close to the theoretical value of −118 mV dec −1 , which indicates that, HER proceeds via a Volmer-Heyrovsky mechanism [33]. The absence of a Tafelian domain at low negative potentials can be explained by the effect of the dependence of hydrogen coverage, , on potential.…”

Calculation of the Hydrogen Surface Coverage and Rate Constants of the Hydrogen Evolution Reaction from Polarization Data

“…The hydrogen evolution reaction (HER) is of particular importance in electrochemistry in view of its relevance to corrosion, electrolytic hydrogen production, electroplating, electrocatalysis, etc. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] Adsorbed hydrogen (H ads ) is an important intermediate in the evolution of electrolytic hydrogen on metal surfaces, 1,4,5,7,8,11,14,16 and also because of its absorption within the metals and the subsequent problem of hydrogen embrittlement. [3][4][5]8,[14][15][16][17] Proper characterization of the mechanism of the HER requires knowledge of the values of the rate constants of the various steps and the degree of surface coverage of the metal with adsorbed hydrogen.…”

Kinetics and electrocatalytic behavior of nanocrystalline CoNiFe alloy in hydrogen evolution reaction

“…Apparently, increase in temperature significantly increases the exchange current densities and decreases the HER overpotentials. The exchange current density obtained from polarization curve for CoNiFe electrode is higher than those reported for Ni and some Ni alloys in alkaline solutions [4,5,[8][9][10][11]14,15].…”

“…On this basis, the specific electrocatalytic activity of CoNiFe electrode is higher than that of Co electrode [39] and is slightly higher than Ni electrode [4,8,15]. Therefore, it can be concluded that an increase in the real surface area is probably the primary reason for the improvement of the electrocatalytic activity of CoNiFe electrode although admittedly some electrocatalytic enhancement is due to the increased specific (intrinsic) activity upon alloying.…”

“…Increase of the electrocatalytic activity of nickel for electrolytic hydrogen evolution has been achieved by the formation of several binary and ternary nickel alloys such as Ni-Mo, Ni-Ti, Ni-Co-Zn [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. Nickel, cobalt and iron binary alloys such as Ni-Co and Ni-Fe have been investigated as electrodes for the HER and it has been observed that these alloys show more specific electrocatalytic activity than nickel [14][15][16].…”