In-house 30 wt.% Pt and 50 wt.% Pt1Ru1 catalysts supported on high-surface area carbon (Ketjenblack, abbreviated as KB) were synthesized by the sulfite complex route. Two different procedures involving either a direct mixing of Pt-sulfite and Ru-sulfite complexes or Pt-sulfite preparation and subsequent impregnation of Ru precursor were adopted for the bimetallic species. In both cases, an impregnation of the formed metal oxides onto KB was adopted to increase the electronic conductivity of the samples. Finally, a carbothermal treatment at 600°C in He atmosphere was carried out for the reduction of the metal oxides to metallic PtRu/C compounds. The Pt1Ru1 ratio was calculated and revealed by X-ray fluorescence (XRF) analysis whereas the carbon percentage was calculated by weight loss. 50 mg of sample was treated in air at 550°C for 2 h and, after cooling, the weight corresponded to 25 mg, confirming a carbonaceous matrix percentage of 50 wt.%. In a similar way, the 30 wt.% Pt/C was determined. X-ray diffraction (XRD) revealed that the samples showed face centered cubic (fcc) structure for Pt nanoparticles. It appears that two distinct crystallographic phases of Pt and Ru nanoparticles were encountered after the synthesis conducted by Ru impregnation. In contrast, only a single fcc phase is visible when the Pt and Ru sulfite precursors were mixed, confirming the formation of an alloy. Furthermore, Scanning Transmission Electron Microscopy-Energy dispersive X-ray spectroscopy (S/TEM-EDX) and X-ray Photoelectron Spectroscopy (XPS) were used to characterize the differences in morphology and surface characteristics of the catalysts. For the electrochemical measurements, rotating disc electrode (RDE) technique under acid and alkaline conditions was employed to investigate the half cell reactions. The catalysts were also deposited at the anode and cathode of fuel cells to evaluate the activity, performance, and short-term durability.
Pt/C and PtRu/C Catalysts Prepared by Modified Sulfite Complex Routes for Fuel Cell Applications
Carmelo Lo Vecchio;Erminia Mosca;Riccardo Dollenz;Angelo Mondello;Vincenzo Baglio
2024
Abstract
In-house 30 wt.% Pt and 50 wt.% Pt1Ru1 catalysts supported on high-surface area carbon (Ketjenblack, abbreviated as KB) were synthesized by the sulfite complex route. Two different procedures involving either a direct mixing of Pt-sulfite and Ru-sulfite complexes or Pt-sulfite preparation and subsequent impregnation of Ru precursor were adopted for the bimetallic species. In both cases, an impregnation of the formed metal oxides onto KB was adopted to increase the electronic conductivity of the samples. Finally, a carbothermal treatment at 600°C in He atmosphere was carried out for the reduction of the metal oxides to metallic PtRu/C compounds. The Pt1Ru1 ratio was calculated and revealed by X-ray fluorescence (XRF) analysis whereas the carbon percentage was calculated by weight loss. 50 mg of sample was treated in air at 550°C for 2 h and, after cooling, the weight corresponded to 25 mg, confirming a carbonaceous matrix percentage of 50 wt.%. In a similar way, the 30 wt.% Pt/C was determined. X-ray diffraction (XRD) revealed that the samples showed face centered cubic (fcc) structure for Pt nanoparticles. It appears that two distinct crystallographic phases of Pt and Ru nanoparticles were encountered after the synthesis conducted by Ru impregnation. In contrast, only a single fcc phase is visible when the Pt and Ru sulfite precursors were mixed, confirming the formation of an alloy. Furthermore, Scanning Transmission Electron Microscopy-Energy dispersive X-ray spectroscopy (S/TEM-EDX) and X-ray Photoelectron Spectroscopy (XPS) were used to characterize the differences in morphology and surface characteristics of the catalysts. For the electrochemical measurements, rotating disc electrode (RDE) technique under acid and alkaline conditions was employed to investigate the half cell reactions. The catalysts were also deposited at the anode and cathode of fuel cells to evaluate the activity, performance, and short-term durability.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
