Support effects in the microstructure and orientation of Mordenite secondary growths

J.M. ZAMARO; M.A. ULLA; E. E. MIRÓ

Zaragoza (España)

Congreso; IZMM2007; 2007

Universidad de Zaragoza

The film characteristics were completely different in the three supports. The XRD and SEM analysis shows coatings with different microstructures, intergrowth and spatial orientation. The Mordenite on Fecralloy® is a dense and highly intergrowth b-oriented film. The Mordenite on CSi foam exhibit a disordered crystalline structure with rough surface zeolite developments. The Mordenite on Cordierite presents a low intergrowth coating with symmetric crystals in c-axisorientation from the support. The different characteristics of the growths results in different catalytic activities for the Nox SCR with CH4 [2]. The results suggest that two factors could be play a role in the growths: the local environment of the growing seeds and the initial disposition of the seeds onto the support surface. The local environment influence can be produced by the different chemical nature of the substrates that can influence the first stages of Mordenite development (The EPMA shows that some elements present in the support migrates into the zeolite growth). The initial disposition of seeds could be influenced by different initial seeds adsorption on the support. The supports having different porosities, surface roghness and electrostactic interaction (IEP) can lead to different preferential adsorption of the Mordenite seeds.