Acid−base and catalytic properties of the products of oxidative thermolysis of double complex compounds

Resumo

Acid–base properties of the products of thermal decomposition of [М(А)₆]_х[М¹(L)₆]_у (where M is Co, Cr, Cu, Ni; M¹ is Fe, Cr, Co; A is NH₃, 1/2 en, 1/2 pn, CO(NH₂)₂; and L is CN, 1/2C₂O₄) binary complexes in air and their catalytic properties in the oxidation reaction of ethanol with atmospheric oxygen are studied. It is found that these thermolysis products are mixed oxides of the central atoms of complexes characterized by pH values of the zero charge point in the region of 4–9, OH-group sorption limits from 1 × 10^–4 to 4.5 × 10⁻⁴ g-eq/g, OH-group surface concentrations of 10–50 nm^–2 in 0.1 M NaCl solutions, and S_sp from 3 to 95 m²/g. Their catalytic activity is estimated from the apparent rate constant of the conversion of ethanol in CO₂. The values of constants are (1–6.5) × 10^–5 s^–1, depending on the gas flow rate and the S_sp value.