Revealing Structural Effects, Part II: The Influence of Molecular Structure on the Adsorption of Butanol Isomers on Platinum

Abstract

The nature of the adsorbates formed when butanol isomers interact with platinum electrodes in a perchloric acid medium was investigated by the application of on-line differential electrochemical mass spectrometry (DEMS) and cyclic voltammetry. In this way, the reactivity of the residues remaining on the electrode surface after a flow-cell experiment was established for the different molecules. It was found that the four isomers form strongly adsorbed species on the electrode, which undergo both electro-oxidation and electroreduction, depending on the potential applied at the electrode. Oxidative stripping of the adsorbates produces CO2 as the only oxidation product, whereas propane and the corresponding butane isomer are obtained on platinum in the hydrogen adsorption potential region. The yields of these hydrocarbons were found to depend strongly on the nature of the butanol isomer and on the adsorption potential. According to these results, it can be concluded that fragmentation of the butanol isomers occurs during adsorption and reduction reactions. C4 alkene and acetyl species are proposed as the adsorbed intermediates in all cases.

Study of the electro-oxidation of a recreational drug GHB (gamma hydroxybutyric acid) on a platinum catalyst-type electrode through chronoamperometry and spectro-electrochemistry

“…The response observed in the electronic current density for the different peaks when GHB concentration and scan rate were changed was used to conclude that the alcohol group is oxidized through a pathway where the corresponding aldehyde and carboxylic acid (succinic acid) are the main products. This previous work is in agreement with the accepted electro-oxidation mechanism of aliphatic alcohols on platinum electrodes [9][10][11][12][13][14].…”

Comparative study of γ-hidroxybutiric acid (GHB) and other derivative compounds by spectroelectrochemistry raman (SERS) on platinum surface

“…Recently, a paper on the electro-oxidation of GHB on a polycrystalline platinum electrode by cyclic voltammetry in acidic medium was released [5]. This work is in agreement with the accepted electrochemical behaviour of aliphatic alcohols on platinum electrodes [6][7][8][9][10][11].…”

Electrochemical behaviour of gamma hydroxybutyric acid at a platinum electrode in acidic medium

“…The cathodic scan yields two main peaks: one corresponding to the reduction of the platinum oxides formed during the anodic scan and one inverted oxidation peak with an onset partially overlapping with the tail of the reduction peak associated to the oxidation of the hydroxyl group of the GHB. This behaviour is similar to the other alcohols as butanol and ethanol with mechanisms of oxidation reactions that are still object of studies on platinum and modified Pt electrodes [15,18,[23][24][25][26]. Also, the oxidation process is influenced by pH and GHB concentration, which can be potentially used for its identification and in sensor design.…”