Stability promotion of Ni/alpha-Al2O3 catalysts by tin added via surface organometallic chemistry on metals - Application in methane reforming processes

This paper reports the effect of selective tin addition to nickel catalysts via a controlled technique (surface organometallic chemistry on metals, SO MC/M), and the performance of the resulting systems in methane reforming pr ocesses: partial oxidation (POM), CO2 reforming (R) and mixed (CO2 + O-2) r eforming (MR), with particular emphasis on their resistance to coke formati on. It is demonstrated that SOMC/M techniques allow to obtain well-defined bimetallic phases in a controlled way. It is found that there is a range of tin concentrations (0.01-0.05 wt.%) for which the stability of the bimetal lic catalysts is markedly enhanced with respect to nickel catalyst, without affecting either the activity level or the selectivity to syngas. These fa cts are explained in terms of a more demanding nature in size of the active sites needed for carbon formation reaction, when compared to methane activ ation reaction to synthesis gas. (C) 2000 Elsevier Science B.V. All rights reserved.