%0 Journal Article
	%A K. Pipitthapan and  S. Maksasithorn and  P. Praserthdam and  J. Panpranot and  K. Suriye and  S. Kunjara Na Ayudhya
	%D 2015
	%J International Journal of Chemical and Molecular Engineering
	%B World Academy of Science, Engineering and Technology
	%I Open Science Index 101, 2015
	%T The Different Roles between Sodium and Potassium Ions in Ion Exchange of WO3/SiO2 Catalysts
	%U https://publications.waset.org/pdf/10001656
	%V 101
	%X WO3/SiO2 catalysts were modified by an ion exchange
method with sodium hydroxide or potassium hydroxide solution. The
performance of the modified catalysts was tested in the metathesis of
ethylene and trans-2-butene to propylene. During ion exchange,
sodium and potassium ions played different roles. Sodium modified
catalysts revealed constant trans-2-butene conversion and propylene
selectivity when the concentrations of sodium in the solution were
varied. In contrast, potassium modified catalysts showed reduction of
the conversion and increase of the selectivity. From these results,
potassium hydroxide may affect the transformation of tungsten oxide
active species, resulting in the decrease in conversion whereas
sodium hydroxide did not. Moreover, the modification of catalysts by
this method improved the catalyst stability by lowering the amount of
coke deposited on the catalyst surface.
	%P 609 - 612