Accumulation of soot in exhaust pipes and chimneys may be avoided through the use of catalytic filters, in which harmful soot is burnt to non-toxic carbon dioxide. JU Faculty of Chemistry scientists are conducting research on cheap material that will allow for burning soot in lower temperatures.

"Soot is created when fuel containing carbon burns without a sufficient amount of oxygen. In such circumstances, the fuel is not fully turned into carbon dioxide, but instead produces undesirable byproducts. These substances, mostly carbon compounds, accumulate in smog and are harmful for man, e.g. by causing carcinogenesis. In addition, soot has a detrimental effect on pulmonary system," said Tomasz Jakubek, Faculty of Chemistry student, third place winner in the FameLab contest.

Catalytic filters help combat the formation of soot. Thanks to them, soot not only does not get through to air, but is burnt to carbon dioxide. Research has shown that it may be burnt in temperature achievable in an exhaust pipe. This is possible thanks to catalysts. "Catalyst is a substance which is not consumed in a chemical reaction, but facilitates it," Tomasz Jakubek explained.

Until now, catalysts for soot burning contained platinum and cerium as well as other elements. However, platinum is very expensive, while cerium resources are slowly depleting. This is why scientists are seeking active, cheaper catalysts.

The JU Faculty of Chemistry research team, led by Prof. Andrzej Kotarba, is working on new solutions, which employ cheap materials, such as iron, manganese, and potassium. Tomasz Jakubek, who conducts his research in the framework of his MA thesis, said that production of this material is amazingly simple. He added that filters that use this catalyst will be much cheaper and more accessible. While in standard conditions soot burns in 500–600 degrees Celsius, the catalyst will lower that temperature to 250.

"One of our most promising projects involves heating manganese dioxide with potassium. We have found that potassium penetrates the structure of manganese dioxide, while new phases such as psilomelane exhibit interesting properties. We call this process nanostructuration," said Tomasz Jakubek, adding that it is impossible to unambiguously determine what mechanisms cause soot to burn more easily, and  thethe hypotheses are currently undergoing the process of verification. One of the theories suggests that the surface of the catalyst allows for easy activation of oxygen atoms in the air, thus making it more "eager" to react with soot. The research is still under way.