The origin of the hysteresis in cyclic voltammetric response of alkaline methanol electrooxidation

Abstract

<p>The mechanism of the alkaline methanol electrooxidation reaction on platinum is complex and not fully understood. However, a better understanding will facilitate reaching the theoretical performance of an alkaline methanol...</p>

Ionomer Significance in Alkaline Direct Methanol Fuel Cell to Achieve High Power with a Quarternized Poly(terphenylene) Membrane

“…They all present five distinct peaks; in the anodic scan peak I is ascribed to hydrogen desorption, and the following peaks (II, III, and IV) are ascribed to adsorption of OH – and formation of different metal oxide species. The cathodic scan presents two peaks: peak V due to reduction of the oxide species and peak VI due to adsorption of hydrogen. ,, There is significant change in current for the catalyst with the m -TPN1-TMA AEI. To further assess the catalyst, the electrochemically active surface area (ECSA) was determined via CO stripping (Figure S2) by using eq . where Q is the CO stripping charge, C is the proportionality constant of 420 μC/cm 2 , and l is the mass loading of catalyst on the electrode.…”

“…The cathodic scan presents two peaks: peak V due to reduction of the oxide species and peak VI due to adsorption of hydrogen. 20,56,57 There is significant change in current for the catalyst with the m-TPN1-TMA AEI. To further assess the catalyst, the electrochemically active surface area (ECSA) was determined via CO stripping (Figure S2) by using eq 1.…”

Noble Metal Based Electrocatalysts for Alcohol Oxidation Reactions in Alkaline Media

“…However, recent studies have suggested alternative interpretations with different rate-determining-step in the forward and reverse scan. For the examples of MOR on Pt in alkaline media, [89][90][91][92] the rate-determining-step in the forward scan is the water dissociation step; while reaction during the reverse scan starts with the oxygenated surface (PtO x ) since Pt surface is oxidized at high potential (>0.74 V vs RHE) [92] after the forward scan, in which case the oxygenated surface of the electrocatalyst is reduced into -OH groups and reactivated, and the alcohol dehydrogenation step becomes the rate-determining-step. As a result, different current peak potential and peak current are commonly observed in the forward and reverse scans.…”

Characterization and Electrocatalytic Features of PtPd and PdPt Bimetallic Nanoparticles for Methanol Electro‐oxidation

“…An opposite effect is displayed when observing a positive shift in the oxide reduction potential by increasing Pt in PdPt BNPs. This potential shift has been linked to forming the oxygen‐containing species and oxide coverage [38,39] . Thus, this observation reveals a lower tendency towards surface oxidation for Pt than for Pd [40] …”

“…In return scan, this MO x coverage is reduced at lower potential. Hence, the current of the backward peak is lower since fewer active sites are available, so during the backward scan, the oxidation of fresh methanol occurs and the reactivation of electrocatalytic surface by reducing MO x [38,39,44] …”