In this paper the catalytic activity of a Fe-Cr WGS catalyst is evaluated in terms of CO conversion and H(2) production. The experimental study has been carried out under realistic conditions typical of oxygen pressurized gasification of biomass. The influence of temperature, excess steam, feed gas composition and space velocity on the activity and selectivity of the catalyst for the WGS reaction is investigated. The experimental work was carried out in a micro reactor testing unit using synthetic gas feed mixtures. Despite the high CO content in the feed gas (44-60% dry basis) the catalyst has shown very good performance at intermediate temperatures 350-450 degrees C, providing hydrogen content increases in the exit gas in the range of 10-17% (dry basis) and CO concentration at the reactor outlet lower than 3% v/v. Best performance operating conditions and the suitability of the catalyst to be incorporated in a palladium membrane reactor is discussed in this article. (C) 2009 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.