Ethanol is an important chemical that has many uses in our everyday life. Its primary use is still in the form of alcoholic beverages, but it is being used more and more as an additive in our gasoline. Most ethanol is made using high temperature distillation from plant matter, usually food crops. Sugars in the plant matter are broken down to ethanol using yeast. This process uses lots of water and heat and produces large amounts of carbon dioxide gas. Scientists at Stanford University have discovered a different method to create ethanol without using plants. The new process produces ethanol from carbon monoxide gas in an electrochemical reaction.
The new method uses two copper electrodes in water saturated with dissolved carbon monoxide gas. Typically, two electrodes in water will produce oxygen gas and hydrogen gas at the electrodes. Copper electrodes will reduce carbon dioxide to ethanol, but are extremely inefficient. The Stanford scientists have found they can greatly increase the efficiency of the reaction using a different type of copper. Their copper is produced from copper oxide nanocrystals layered into a network of crystals with discrete edges. They believe the discrete edges are the key to the improved efficiency. They also found they could continue the reaction to create propanol by slightly altering the composition of the copper oxide crystals.
This technique could be useful in current ethanol distillation facilities by reclaiming the carbon dioxide produced during the fermentation process, converting it to carbon monoxide to produce more ethanol.