CuO based catalysts on modified acidic silica supports tested in the de-NO x reduction

Abstract

A series of dispersed CuO catalysts supported on modified silica supports with Al 2O 3 (SA), TiO 2 (ST), and ZrO 2 (SZ) were prepared optimising the adsorption method of copper deposition assisted by ultrasound treatment, already reported in a previous paper (S. Bennici, A. Gervasini, V. Ragaini, Ultrason. Sonochem. 10 (2003) 61). The obtained catalysts were characterized in their bulk (atomic absorption, X-ray diffraction, temperature programmed reduction) and surface (N 2 adsorption, X-ray photoelectron spectroscopy, scanning electron microscopy) properties. The morphology of the finished materials was not deeply modified compared with that of the relevant supports. The employed complemented techniques evidenced a well dispersed CuO phase with a copper-support interaction on the most acidic supports (SA and SZ). The catalyst performances were studied in the reaction of selective catalytic reduction of NO x with ethene in oxidizing atmosphere in a flow apparatus under variable times (0.360–0.072 s) and temperatures (200–450 °C). The catalysts prepared on the most acidic supports (SA and SZ) were the most active and selective towards N 2 formation. They showed a particular interesting activity in the reaction of NO 2 reduction besides that of NO reduction.