Fig. 2

Structural characterizations of the two catalysts. TEM and HRTEM images of the CoO_xPt/TiO₂ (a, b) and CoO_x/TiO₂/Pt (c, d) catalysts. e STEM image of the CoO_x/TiO₂/Pt catalysts and the corresponding EDS mapping profiles in rectangular area. Scale bars: a, c and e 50 nm; b and d 5 nm