Potassium improved stability of Ni/MgO in the steam reforming of ethanol for the production of hydrogen for MCFC

The catalytic behavior of the bare and K-promoted 21% Ni/MgO catalyst in the ethanol steam reforming at MCFC operative conditions has been investigated. The effect of K loading (1-3 wt.%) on the catalytic activity, stability and coking rate have been addressed. K addition stabilizes Ni catalyst mainly by depressing the metal sintering, while coke formation does not seem to be influenced by alkali addition. Endurance test (500 h(-1)) performed at 20,000 h(-1) allows foresee a very long catalyst life in the case of practical application. High H-2 productivity ( > 5 mol H-2/mol fed ethanol) was obtained. A change in the electronic properties of the active phase accounts for the effect of K addition on the catalytic behavior of the Ni/MgO catalyst. (C) 2004 Elsevier B.V. All rights reserved.