ESR study of the deactivation of Cu-ZSM-5 in a net oxidizing atmosphere

Influence of lattice stability on hydrothermal deactivation of Cu-ZSM-5 and Cu-IM-5 zeolites for selective catalytic reduction of NOx by NH3

“…As the 32 Cu-Al clusters only form once Al is detached from the framework, the stability of Al in the zeolite 33 framework is proposed to dictate the overall hydrothermal deactivation behavior of Cu-ZSM-5 and 37 38 Selective catalytic reduction (SCR) of nitrogen oxides (NO x ) with NH 3 is an important technology 39 for reducing environmentally harmful NO x in the exhaust gases from vehicles, ships, and power 40 plants to the emission levels required by legislation. As legislation is becoming more stringent 41 further development of SCR-technologies and a better understanding of the catalytic materials are dispersed [11], and in this case the stability of the zeolite framework should be less important When 70 copper is loaded into zeolite structures containing small pores, such as the CHA or AEI topologies, 71 a more stable activity is observed, possibly because of the limited migration of detached aluminum 72 moeities inside the pores [12,13]. Still, the deactivation mechanism of Cu-zeolites, in particular how 73 dealumination and migration of Cu and Al occur, is not clear.…”

Pillared Clays as Superior Catalysts for Selective Catalytic Reduction of Nitric Oxide

“…Two reasons were proposed for the deactivation. One was competitive adsorption for the active sites by H2O and SO2; the other was framework dealumination of 15 ZSM-5 after it was subjected to prolonged exposure to wet exhaust gas at high temperatures [40][41][42]. The former was reversible; the latter was irreversible.…”

“…Like Cu-ZSM-5, the catalytic activity on the Ce-Cu-Al-MCM-41 catalyst decreased in the presence of H2O and SO2. The inhibition of catalytic activity by H2O and SO2 has been extensively studied on Cu-ZSM-5 catalyst [40][41][42]. Two reasons were proposed for the deactivation.…”

Facile synthesis and characterizations of copper–zinc-10,15,20-tetra(4-pyridyl) porphyrin (Cu–ZnTPyP) coordination polymer with hexagonal micro-lump and micro-prism morphologies

“…According to the electrons layout of copper atom, there is a single unpaired electron existing in Cu (II).The chemical states of copper ions in the as-prepared solid samples could be measured by using ESR tool [22][23][24]. …”