Reaction Mechanism at Cu Electrode

Reference 19-Reproduced by permission of The Royal Society of Chemistry. 

Electronation of CO in the gas phase readily gives rise to carbon atoms and 0 ions. Kim et al. proposed electrochemical splitting of CO in CO reduction on a Cu electrode. They rationalized an elementary step of surface carbon atom formation from CO molecule on a Cu elecrode, 

The partial current of CH4 formation is widely scattered when plotted against the potential. With an assumption that the partial current is proportional to proton activity, a linear Tafel relationship is obtained as shown in Fig. 25.The transfer coefficient is determined as 1.33. These facts indicate that the rate determining step of CH4 formation is involved with the second electron transfer to a hypothetical intermediate species such as COH in an electrochemical equilibrium with a CO adsorbed on the electrode and a proton from the electrolyte, 

Neither C2H6 nor CH3OH is produced from a Cu electrode, and Cu is an inert metal for thermochemical Fischer-Tropsch reac-tion Thus few adsorbed hydrogen atoms will be present on Cu electrode surface. One can presume that hydrogen species is composed of two hydrogen atoms, such as whereas the presence 

The production of alcohols is accompanied with the corresponding aldehydes in both CO and CO2 reduction. Since aldehydes are electrochemically reduced to the corresponding alcohols at Cu electrodes, alcohols will be formed with intermediate formation of aldehydes. Aldehydes would be produced with insertion of CO 

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