May 21, 2012
Reaction Uses Carbon Dioxide To Make Carbon-Based Semiconductor
A materials scientist at Michigan Technological University has discovered a chemical reaction that not only eats up the greenhouse gas carbon dioxide, it also creates something useful. And, by the way, it releases energy.
Making carbon-based products from CO2 is nothing new, but carbon dioxide molecules are so stable that those reactions usually take up a lot of energy. If that energy were to come from fossil fuels, over time the chemical reactions would ultimately result in more carbon dioxide entering the atmosphere–defeating the purpose of a process that could otherwise help mitigate climate change.Professor Yun Hang Hu´s research team developed a heat-releasing reaction between carbon dioxide and Li3N that forms two chemicals: amorphous carbon nitride (C3N4), a semiconductor; and lithium cyanamide (Li2CN2), a precursor to fertilizers.
“The reaction converts CO2 to a solid material,” said Hu. “That would be good even if it weren´t useful, but it is.”
And how much energy does it release? Plenty. Hu´s team added carbon dioxide to less than a gram of Li3N at 330 degrees Celsius, and the surrounding temperature jumped almost immediately to about 1,000 degrees Celsius, or 1,832 degrees Fahrenheit, about the temperature of lava exiting a volcano.
Hu´s work is funded by the National Science Foundation and detailed in the article “Fast and Exothermic Reaction of CO2 and Li3N into C—N-Containing Solid Materials,” authored by Hu and graduate student Yan Huo and published in the Journal of Physical Chemistry.
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