SEM Studies of Discharge Products from Alkaline Iron Electrodes

Abstract

Anodic oxidation products in 5NKOH of both planar and porous iron electrodes have been investigated with SEM techniques. On the first discharge level well‐defined crystallites of normalFefalse(OH)2 are formed, while on continued discharge the products become sludge formed, probably consisting of hydrated normalFeOOH . The morphologies support the dissolution‐precipitation mechanism during the first discharge step. The second anodic level proceeds probably via migration of ions and electrons in the solid phase. The crystallite size increases with temperature which depends on that the relative supersaturation decreases.

Redox and electrochemical water splitting catalytic properties of hydrated metal oxide modified electrodes

“…84 These various features, reflecting surface redox processes involving surface bound oxy iron species, have been assigned by a number of authors in the literature. [186][187][188][189][190][191][192][193][194][195] Our current viewpoint is primarily informed by the work of Burke and Lyons. 84 Peak A1 is most probably due to the formation of a layer of adsorbed hydroxy species,…”

Electricity generation and recovery of iron hydroxides using a single chamber fuel cell with iron anode and air-cathode for electrocoagulation

“…Furthermore, most authors [54][55][56][57][58][59][60][61][62] agree that the formation of Fe(OH) 2 is the first step in the formation of a passive layer and reaction (10) is the dominant reaction at pH values close to 9. The second oxidation step is shown in reactions (11) …”

Redox switching and oxygen evolution electrocatalysis in polymeric iron oxyhydroxide films

“…The various features have been previously assigned, both by us, 12 and other workers. [14][15][16][17][18][19][20][21][22][23][24] Our viewpoint on the voltammetric peak assignment is summarised presently.…”

“…y SOH E y -1 or 0. Indeed, where the Temkin isotherm applies, the rate equations for step (C I) in the forward and reverse directions are identical to eqn (14) and (15), respectively, while the general rate equation for the rate determining (C II) step takes the same form as eqn (16). However the simplification that previously took us from eqn (16) to (17) is not permissible for pathway C. In the case of the chemisorbed O atom formed in step (C II), the Temkin parameter r II is likely to be similar in magnitude to r SOH , since both the SOH and SO intermediate species involve chemical bonding by oxygen atoms to the substrate S. Setting r SO = r SOH = r, substituting into eqn (16) and as before setting g = 1/2 yields:…”