Study of PdIn-zeolite catalysts by XPS and TEM-EDX

HERNÁN DECOLATTI; FERENC LÓNYI; MAGDOLNA MIHÁLYI; JÓZSEF VALYON; ALICIA BOIX; LAURA GUTIERREZ

Valencia

Conferencia; 5th International FEZA 2011 conference; 2011

The selective catalytic reduction of NOx with methane in the presence of oxygen excess (NOx-SCR) is a promising method to reduce the NOx emission of power plants fuelled by natural gas [1]. The transition metals-zeolite catalysts are able to activate the relatively stable methane molecule for the reaction. Several studies suggest that indium-containing zeolites show significant activity in the NOx-SCR [2,3]. The catalytic activity is generally attributed to cationic indium species. On the other hand, Pd zeolites have also been reported as active catalysts for the mentioned reaction [4] but they deactivate due to the agglomeration of Pd cations into bulky PdO particles outside of the zeolite pore structure.We recently achieved a significant improvement in catalytic activity using PdInHM catalysts [5]. To avoid the problems of pressure drop and improve the transfer of energy and mass, the powders are normally washcoated on monolithic supports. It is crucial to obtain structured catalysts with catalytic properties similar to the powders. In this work, monolithic PdInZeolite catalysts were prepared by washcoating. Fresh and used catalysts were characterized by XPS and TEM-EDX techniques to establish a relationship with the catalytic activity of solids.