NOx conversion properties of a novel material: Iron nanoparticles stabilized in carbon

作者：Busch Martin; Kompch Alexander; Suleiman Samer; Notthoff Christian; Bergmann Ulf; Theissmann Ralf; Atakan Burak; Winterer Markus^*

来源：Applied Catalysis B: Environmental , 2015, 166: 211-216.

DOI：10.1016/j.apcatb.2014.11.013

• Iron nanoparticles
• Core-shell particles
• Nitrogen oxide conversion
• Carbon
• Nitrogen oxide adsorption

Nitrogen oxides (NOx) belong to the most common pollutants from combustion processes and are a major threat to human health. Carbon-based catalysts exhibit strong advantages for NOx removal like low-toxic application and easy handling. However, gasification of the carbon matrix at elevated temperatures is still one of the greatest concerns. Hence, we have directed our focus on especially low temperature NOx-removal using a novel material, iron nanoparticles stabilized in a carbon matrix (nano-Fe/C). The investigations included NO2 uptake properties and catalytic conversion of NO2 in recycle flow at 425 K and 328 K, scanning transmission electron microscopy and 77 K-N-2-adsorption.
Nano-Fe/C exhibits superior NOx-removal properties compared with untreated or iron-infiltrated activated carbon or magnetite reference catalysts. No severe catalyst deactivation or catalyst aging at 425 K is observed. Even at 328 K nano-Fe/C still exhibits NO2-conversion, although without converting the product NO. NO2 adsorption at 297K is suggested to occur in three stages with different kinetics: (1) NO2 adsorption and reduction to NO, (2) physisorption on the oxidized catalyst surface and (3) saturation of the catalyst and diffusion into the substrate matrix. At 425 K, NO2 is quickly reduced to NO and the resulting NO is further converted to N2O. After complete consumption of NO, the residual NO2 is also converted to N2O. A possible reaction mechanism is suggested based on the conversion kinetics.

• 出版日期2015-5