Chinese scientists have created a new catalyst based on iron nanoparticles, capable of "forever" converting ordinary carbon dioxide and hydrogen into a mixture of hydrocarbons, similar to gasoline, according to an article published in the journal Nature Communications.
“Over the past 200 years, coal, oil and gas have been the main engines of our civilization, the basis of its economic and social development. Combustion of fuel has led to the release of a huge amount of CO2 into the atmosphere, which today is causing negative climate change. Converting CO2 into fuels and chemicals will not only help us fight warming, but also solve the problem of resource depletion,”said Jian Sun of the Institute of Chemical Physics in Dalian, China and his colleagues.
In recent years, scientists have been actively trying to find a way to convert atmospheric CO2 into biofuels and other useful substances. For example, last July, physicists in Chicago designed a solar cell that uses light energy to break down CO2 and produce carbon monoxide and hydrogen, and in October their colleagues at Oak Ridge National Laboratory created a catalyst that converts carbon dioxide into regular alcohol.
In principle, both can already be used for energy storage, but these catalysts have two major drawbacks. They quickly fail and require cleaning after several tens of hours of operation, and also release many by-products.
Sun and his team solved both of these problems - their catalyst converts virtually all of the carbon dioxide into hydrocarbons that form the basis of gasoline and other high-octane fuels, while operating at least 1000 hours (one and a half months) in "normal" industrial conditions.
It consists of two components - nanoparticles of a compound of iron oxide and sodium, as well as the so-called zeolites. Zeolites are hollow nanoparticles of aluminum silicate, which are widely used today for water purification and for "packing" various catalysts, the entry of molecules of which into the zeolites noticeably changes their properties and often makes them behave much more actively than in free form.
As the scientists note, each component plays a different role in this case - iron nanoparticles "break" carbon dioxide molecules and force it to combine with hydrogen atoms, and zeolites and their fillings contribute to the unification of such "semi-finished products" into long chains of hydrocarbons.
The combination of these components, according to Chinese chemists, makes it possible to achieve the actual "eternity" of such a catalyst. Its effectiveness, as noted by scientists, decreased by only 6% in the first 300 hours of operation and then did not change, which indicates that it is stable and will remain in this form much longer than 1000 hours. In addition, 96% of carbon dioxide is converted to a gasoline analogue, and only 4% of CO2 is converted to methane.
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Moreover, the “bouquet” of hydrocarbons can be flexibly changed by increasing or decreasing the proportion of hydrogen and CO2 in the mixture and by varying the type of zeolite that is used as “packing” for iron nanoparticles. By using solar panels as a source of energy to heat this mixture of gases and pump it through a catalyst, it is possible to efficiently and fairly cheaply store solar energy in the form of a common fuel for all, without causing harm to the environment, Sun and his colleagues conclude.