Preparation and characterization of Pt nanoparticles supported on a Fe-doped hydroxyapatite-activated Vulcan XC72 composite material

In this research, the hydroxyapatite (HAp) could be directly deposited on carbon black (CB), which was the modified surface to generate more OH- free radicals to strengthen the bond between HAp and CB, before adding ((NH4)(2)Fe(SO4)(2)center dot 6H(2)O) to engage the ion exchange with Fe2+ and Ca2+ to obtain FeHAp-CB composites. The Pt nanoparticles were then reduced on the FeHAp-CB composite surface to derive a Pt/FeHAp-CB catalyst of dual function. The catalyst revealed a steep desorption peak at -0.180 V (vs Ag/AgCl) in a hydrogen oxidation reaction ascribed to the characteristics of Pt (110) facet and the CO detoxication function in the methanol oxidation reaction. The superior performance of Pt/FeHAp-CB/CB catalyst was apparently related to the Pt (110) surface, the Fe concentration, and the homogeneous dispersion of Pt particles on the FeHAp-CB composites. And, the ratio of coexisting Pt-0 and Pt2+ within Pt/FeHAp-CB/CB catalyst would definitely affect chemical stability and mass activity. By X-ray photoelectron spectroscopy (XPS), it was found that a high quantity of Pt-0 could improve mass activity, while a high quantity of Pt2+ contributed to chemical stability.