Regeneration of spent three-way catalysts with nano-structured platinum group metals by gas and acid treatments.
The influence of physicochemical treatments on the catalytic activity of the spent nano-structured three way catalysts (TWCs) was examined to evaluate the possibility of using spent TWCs for removing VOCs. Thermal gases and acid aqueous solutions were used to regenerate the spent nano-structured TWCs. The characterization of the spent catalyst and its modified forms was carried out by using XRD, TEM, ICP, and N2 adsorption-desorption isotherms. The catalytic activity tests revealed that the spent nano-structured TWCs have a great potential for removing toxic compounds. The activities of catalysts were also found to be highly dependent on the treatment conditions. The acid aqueous treatments were very useful for improving the catalytic activity because they removed various contaminants such as fuel additives, lubricant oil additives, and metallic compounds. However, the thermal gas treated TWCs were less active than the parent TWCs. Furthermore, the activities of the catalysts treated with acids were closely connected with the remaining Pt/Al ratios.
Kim
Sang Chai
SC
Department of Environmental Education, Mokpo National University 61 Dorim-ri, Cheonggye Myeon, Muan 534-729, Korea.
Nahm
Seung Won
SW
Wang
Geun Shim
GS
Seo
Seong Gyu
SG
Lee
Jae Wook
JW