Improvement in the durability of carbon black-supported Pt cathode catalysts by silica-coating for use in PEFCs

Influence of Cathode Catalyst Layer with SiO2-Coated Pt/Ketjen Black Catalysts on Performance for Polymer Electrolyte Fuel Cells

“…In this study, it will not mention the information about analysis results for SiO 2 -Pt/KB catalysts because we focused on the catalyst layer containing SiO 2 -Pt/KB. The information about SiO 2 -Pt/KB can be found in Takenaka group's papers [10,12,18]. For SiO 2 -Pt/KB catalyst used in this study, it was confirmed that the SiO 2 layer was coated on the surface of catalysts by TEM images.…”

“…When the Pt/KB is covered by SiO 2 layers, Pt particles located inside pores cannot obtain the protons because SiO 2 layers block water which penetrates into inside Pt particles. In order to support this assumption, the experimental results of Takenaka et al were considered [18]. They examined the adsorption isotherms of water vapor on Pt/KB, SiO 2 -Pt/KB with hydrophilic SiO 2 groups, and CH 3 -SiO 2 /Pt/KB with hydrophobic SiO 2 groups, at 298 K. Adsorbed amount of water rose with the increase in water vapor pressure for all catalysts.…”

“…Ketjen black-supported Pt catalyst (TEC10E50E, 46.5 mass% Pt) was purchased from Tanaka Kikinzoku Kogyo, and denoted as Pt/Ketjen Black. SiO 2 -coated Pt/Ketjen black was prepared by hydrolysis and polycondensation of SiO 2 sources such as tetraethoxysilane (TEOS) and 3-aminopropyltriethoxysilane (APTES) in the same way as the SiO 2 coating method used in Takenaka group's paper [18]. First, Pt/KB/distilled water mixture was sonicated and then NH 3 was added to adjust the pH value up to 10.…”

Poly[2,2′-(4,4′-bipyridine)-5,5′-bibenzimidazole] functionalization of carbon black for improving the oxidation stability and oxygen reduction reaction of fuel cells

“…7 This structure leads CB to a fast oxidation process under the acidic operating conditions of FCs. 8 Thus, it is important to offer an advanced formulation route for CB into the CL to reach its optimum use in PEFCs.…”

“…To gain a better understanding of the degradation performance of both catalysts, STEM images (surface and transmittance) were captured aer the durability tests (see Fig. 7 and 8). As seen, the Pt-NPs sintered and agglomerated in both catalysts.…”