Mono-metallic Pt and Rh catalysts supported on both CeO2 and TiO2 were prepared and tested for water-gas shift activity in a Flowrence, high throughput reactor system. The feed composition mimicked a typical fuel processor, steam methane reformer outlet stream. The Pt/CeO2 catalyst showed the best metal activity of ∼3.8 E-07 moles CO converted·gPt-1 s-1, at a Pt loading of 0.5 wt%, activity decreasing with increasing metal loading. Furthermore, the Pt/CeO2 catalyst produced almost no methane while the Rh based catalysts led to substantial methanation.