Investigation on the coordination mechanism of Pt-containing species and qualification of the alkaline content during Pt/C preparation via a solvothermal polyol method

A solvothermal assisted ethylene glycol reduction method is a common technology for Pt/C catalysts preparation. Here, the coordination mechanism of the Pt-containing species is deeply studied by innovatively adopting the ultraviolet-visible spectroscopy technology and H+ concentration detector. Moreover, the amount of NaOH that effectively coordinates Pt4+ has been tentatively qualified and the heating parameters during the preparation process of Pt/C have also been optimized. As investigated, the optimized 20-(1/22)-140-2 Pt/C (20 wt%Pt; m(Pt):m(NaOH)=1/22; heating temperature: 140°C, heating time: 2 h) exhibits higher electrocatalytic activity towards oxygen reduction reaction (ORR) than the commercial 20 wt% Pt/C (E-TEK) in acidic media. This work provides a theoretical reserve and technical accumulation for industrialized mass production of highly efficient Pt/C catalysts for ORR in proton exchange membrane fuel cells.