Cities are on the frontlines of global climate change. We urgently need to reduce the amount of activities that create excessive carbon dioxide, smog and other greenhouse gasses. If at all possible, it will be a long way to completely prevent the emission of harmful greenhouse gasses caused by human activities. What kinds of options are available to deal with this situation? Maybe the coincidentally found solution from Oak Ridge National Labs?
Thanks to ORNL nanocatalyst CO₂ can be seen as chemical feedstock
Instead of perceiving carbon dioxide as a harmful waste product, it can be used as a raw material to produce ethanol if things go the way researchers from the United States want. Scientists at the Department of Energy’s Oak Ridge National Laboratory (ORNL) developed a new waste-to-fuel technology. A nanocatalyst with small spikes of carbon and copper is able to convert CO₂ to ethanol.
“We discovered somewhat by accident that this material worked,” said ORNL’s Adam Rondinone, lead author of the team’s study published in ChemistrySelect. “We were trying to study the first step of a proposed reaction when we realized that the catalyst was doing the entire reaction on its own.”
Nanocatalyst does not consist of exotic and uncommon materials
Furthermore, the nanocatalyst does not consist of exotic and uncommon materials. Expensive metals like platinum are not needed. The secret lies in Cu nanoparticles on a highly textured, N-doped carbon nanospike fil. Graphite, the crystalline form of carbon, is an abundantly available resource and occurs in many parts of the world. The provision of copper can be realized for decades trough recycling and the exploitation of reserves. Nitrogen, a further component, is the most common pure element in the earth. “By using common materials, but arranging them with nanotechnology, we figured out how to limit the side reactions and end up with the one thing that we want,” Rondinone said.
Nanocatalyst turns carbon dioxide into ethanol with a yield of 63 percent
According to the scientists, the catalyst possesses various advantages. With a Faradaic efficiency of 63 percent (at −1.2 V vs RHE), the nanocatalyst generates ethanol with a comparatively high proportion of transferred electrons during the electrochemical reaction. Additionally, with a selectivity of 84 percent, a large fraction of the feed can be converted into ethanol. Selectivity can be stated as the rate of conversion of the feed to the desired product divided by the total conversion rate of the feed. Furthermore, the electrochemical process runs in water at ambient pressure and temperature. This means there is no energy needed to generate differences in pressure and temperature. “We’re taking carbon dioxide, a waste product of combustion, and we’re pushing that combustion reaction backward with very high selectivity to a useful fuel,” Rondinone said. “Ethanol was a surprise — it’s extremely difficult to go straight from carbon dioxide to ethanol with a single catalyst.”
Because of the mentioned advantages, the researchers think about a scale-up for industrial applications. Energy surpluses from renewable sources like wind and sun can probably be stored as ethanol after conversion. “A process like this would allow you to consume extra electricity when it’s available to make and store as ethanol,” Rondinone said. “This could help to balance a grid supplied by intermittent renewable sources.”