text: Catalysts can be grouped by their primary products. Several metal  are unfit for CORR because they promote to perform hydrogen evolution instead. Electrocatalysts selective for one particular organic compound include tin or bismuth for formate and silver or gold for carbon monoxide. Copper produces multiple reduced products such as methane, ethylene or ethanol, while methanol, propanol and 1-butanol have also been produced in minute quantities.
  Three common  products are carbon monoxide, formate, or higher order carbon products (two or more carbons).