Reduction in Aqueous Solutions at Metal Electrodes

In aqueous solution, primary interest centers on the production of CO, formic acid, methanol and alcohols, and methane and hydrocarbons. The standard redox potentials (versus the saturated calomel electrode, SCE) for the common C02 reduction products of formic acid, CO, formaldehyde, methanol, and methane in aqueous solution at pH 7.0 are given as [42]  

The similarity of the reduction potentials for H+ to hydrogen, and for C02 to various products, explains the issue of competing hydrogen evolution in aqueous solution. Thus, there has been much interest in high hydrogen overpotential metals that provide slow kinetics for H+ reduction. 

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