Evidence for a high oxygen mobility in Li/MgO

The oxidative properties of Li/MgO in the absence of O₂ were studied at 730° C using C₂H₄ as a reducing agent and a multisectional flow stainless steel tubular reactor. Large amounts of CO and H₂ were determined. It was demonstrated that Li/MgO exhibited a high oxygen mobility. The exchange capacity was (2.4-4.0) × 10²⁰ oxygen atoms per 1 g of the catalyst and the period of oxygen donation was 150 h or more. After the catalyst reduction, its oxygen transfer ability was fully restored by re-oxidation in the stream of air. Oxidation of C₂H₄ to CO and H₂ was accompanied by its decomposition to C and H₂. The ratio ΔH₂/ΔC₂H₄ was found to be 1.91 ± 0.13 independently of the oxidation state of the catalyst, the location of the sampling point along the catalyst bed (and the post-catalytic zone) and the duration of the experiment. The mechanism was discussed.