Solid-State Interactions in Li-Doped Ni/MgO Catalysts
Journal of the Chemical Society - Faraday Transactions (1990-1998, in 1999 become Physical Chemistry Chemical Physics)
Dipartimento di Chimica Industriale, Universita` degli Studi di Messina, Salita Sperone c.p. 29,
I-98166 S. Agata, Messina, Italy
Istituto CNR-T AE, Salita S. L ucia 39, I-98126 S. L ucia, Messina, Italy
Boreskov Institute of Catalysis, Prospekt Akademika L avrentieva 5, 630090 Novosibirsk, Russia
The effects of the addition of Li (Liat:Niat ≈ 1:3) on the structure and reducibility of a 19% Ni/MgO catalyst, calcined at TC 400–800 °C, have been investigated by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), temperature-programmed desorption and reduction (TPD and TPR) and transmission electron microscopy (TEM). Li causes melting of the MgO matrix, markedly altering the morphology of the Ni/MgO catalyst. Li enhances the diffusion of Ni ions into the MgO lattice and the consequent formation of an NixMg(1−x)O solid solution. Li also promotes the reduction of the Ni/MgO system, enabling easier extraction of Ni2+ ions located in the MgO lattice. Solid-state interactions accounting for marked changes in both the physico-chemical properties and the reactivity of the Li-doped Ni/MgO catalyst are highlighted.