Abstract
Exhaust from diesel engine contributes a main part in both PM10 and PM2.5 problem. Polycyclic aromatic hydrocarbons (PAHs) in diesel fuel should be considered because of their toxicity. Worldwide Fuel Charter recommends the PAHs content less than 2 wt.% in diesel fuel for less toxic of diesel exhaust emission. Nickle Molybdenum Sulfide over Gamma alumina (NiMoS/ 3-Al2O3) catalyst is generally used in hydrotreating processes of petroleum refinery. PAHs are saturated by hydrogenation reaction (HYD) to be mono-aromatic or non-aromatic called Hydrodearomatization (HDA) process. However NiMoS/ 3-Al2O3 catalysts still require improvements of HYD activities. Gamma alumina has been widely used as catalyst support which generally possesses only Lewis acidity. This work focuses on surface modification of 3-Al2O3 by ammonium fluoride to generate Br?nsted acidity which could improve HYD function of NiMoS catalysts. All 3-Al2O3 supports were characterized by In-situ pyridine adsorption Diffuse Reflectance Infrared Fourier Transform spectroscopy (Pyridine-DRIFT). Increment of fluorine content in the modified 3-Al2O3 leads to increase its Br?nsted acidity. The NiMoS over modified 3-Al2O3 exhibits higher HYD activities than that of the 3-Al2O3. Generation of Br?nsted acidity on -Al2O3 support can enhance the HYD function of NiMoS catalyst for HDA process of clean diesel production. ? Published under licence by IOP Publishing Ltd.
