Adsorption-desorption properties of clinoptilolites and the catalytic activity of surface Cu(II)–Pd(II) complexes in the reaction of carbon monoxide oxidation with oxygen

Chem. Met. Alloys 4 (2011) 213-218

https://doi.org/10.30970/cma4.0186

T.L. Rakitskaya, T.A. Kiose, V.O. VASYLECHKO, V.Ya. Volkova, G.V. GRYSHCHOUK

Adsorption-desorption properties of natural and acid-modified clinoptilolite (N‑CLI and H‑CLI, respectively) with respect to Cu(II) and Pd(II) have been studied. It has been found that an acid-thermal treatment (3M НNO₃, T = 373 K, 6 h) of N‑CLI weakens the palladium bonding to the H‑CLI‑6 surface with a fraction of weakly bound palladium(II) of 71.2 % and this alone determines the activity of the K₂PdCl₄–Cu(NO₃)₂ / H‑CLI‑6 catalyst during carbon monoxide oxidation. The bonds that copper(II) forms with the H‑CLI‑6 surface can be divided into weak (30 %), medium-strength (40 %), and strong (30 %) ones, however, the contribution of weakly bound copper(II) amounts to only 4 % of the K₂PdCl₄–Cu(NO₃)₂ / H‑CLI‑6 catalytic activity.

Time dependence of the activity of K₂PdCl₄-Cu(NO₃)₂ / H‑CLI‑6 samples in the carbon monoxide oxidation with oxygen under different conditions of copper(II) desorption.

Keywords

Adsorption-desorption of copper(II) and palladium(II) / Natural and acid-modified clinoptilolite / Catalyst for carbon monoxide oxidation