Fig. 2. SEM images from the secondary and back-scattered electron signals (SE, BSE) of catalysts (a) SE Ir-black and (b) BSE Ir-black; (c) SE Ir-nano H₂O; (d) BSE Ir-nano 91.5; (e) BSE Ir-nano 99.5\CTAB; (f) BSE Ir-nano 99.5; (g) BSE Ir-nano 99.8; and (h) BSE Ir-nano 99.8-P, (i) SE Ir-nano 99.8-P.