Electrocatalytic activity and durability of Pt/NbO2 and Pt/Ti4O7 nanofibers for PEM fuel cell oxygen reduction reaction

Abstract

a b s t r a c tIn this paper, we report the synthesis of both NbO 2 and Ti 4 O 7 nanofibers using an electrospinning technique in an effort to use metal oxides as a possible replacement for carbon as PEM fuel cell catalyst supports. The synthesized nanofibers are physically characterized using several methods including XRD, SEM, TEM, BET, ICP-MS as well as XPS. The thermal, chemical, and electrochemical stabilities as well as the electronic conductivities of these two supports are also evaluated in order to check their feasibility as catalyst supports in the temperature range of 95-200• C. Two catalysts, 20-wt% Pt/NbO 2 and 20-wt% Pt/Ti 4 O 7 , are prepared and tested for both ORR mass activity and stability in acidic solution. XPS measurements of samples analyzed before and after the durability tests suggest the formation of electronically insulating surface oxides, which can be partially responsible for both low ORR mass activity and catalyst durability.Crown

Energy-saving synthesis of electrolytic manganese dioxide using oxygen cathode with Pt/TiO2-CNx nanocatalysts

“…Pt/TiO 2 -CNx displayed higher activity than Pt/C, which may be due to the higher amounts of active sites provided by Pt nanoparticles and high electric conductivity of CNx nanowires for the oxygen reduction reaction than Pt/C (Fig. 5); moreover, some TiO 2 particles became Ti 4 O 7 , which significantly [36]. The BET specific surface area is calculated to be 131.677 m 2 /g for Pt/TiO 2 -CNx; however, the Pt/C catalyst has a high BET surface area of 208.871 m 2 /g.…”

Niobium Dioxide Facilitating Methanol Electrooxidation on Pt/C Catalyst by Synergistic Effect

“…Therefore, niobium dioxide (NbO 2 ) with electronic configurations of 4d 1 has abstracted increasing attention [22,23]. Orilall et al [24] reported that Pt-Pb nanoparticles incorporated into mesoporous NbO 2 -carbon composites showed high mass activity toward formic acid electrooxidation.…”

Electrocatalysis of titanium suboxide-supported Pt–Tb towards formic acid electrooxidation

“…Carbon black is a commonly used support in fuel cells, but the corrosion of the carbon support would cause a negative impact on the working efficiency and performance of fuel cells [14]. Recently, Ti 4 O 7 has been found to be a promising support material owing to its higher corrosion resistance and superior electrical conductivity than carbon black [15]. In our previous work [16], it is shown that Pt catalyst supported on Ti 4 O 7 possesses better catalytic activity and stability than Pt catalyst supported on carbon black and commercial TiO 2 for formic acid electrooxidation.…”