Fig. 3

Ultraviolet photoelectron spectra of Pt-decorated Co-Pd and controls. The work function of Pt-decorated Co-Pd (Co@Pd-Pt/carbon nanotube (CNT)) catalyst is lower than that of the control samples including Pt/CNT, Pd/CNT, Pd-Pt core-shell (Pd@Pt/CNT), and Co-Pd core-shell (Co@Pd/CNT) catalysts