Adapting of sol–gel process for preparation of TiB2 powder from low-cost precursors

Carbon corrosion is a severe issue limiting the long-term stability of carbon-supported catalysts, in particular in the highly dynamic conditions of automotive applications. (Doped) oxides have been discussed as suitable alternatives to replace carbon, but often suffer from poor electron conductivity. That is why non-oxide ceramics, such as tungsten carbide and titanium nitride, have been discussed recently. Titanium diboride has also been proposed, due to its promising activity and stability in an aqueous electrochemical cell. In this work, Pt nanoparticles were deposited onto μm-sized TiB 2 particles with improved grain size, manufactured into porous gas diffusion electrodes and tested in a realistic polymer electrolyte membrane (PEM) fuel cell environment. In contrast to the model studies in an aqueous electrochemical cell, in the presence of oxygen and high potentials at the cathode side of a real fuel cell, TiB 2 becomes rapidly oxidized as indicated by intensely colored regions in the membrane-electrode assembly (MEA). Moreover, already the electrode manufacturing process led to the formation of titanium oxides, as shown by X-ray diffraction measurements. This demonstrates that Cyclic Voltammetry (CV) measurements in an aqueous electrochemical cell are not sufficient to prove stability of novel materials for fuel cell applications. OPEN ACCESSEnergies 2014, 7 3643

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“…The carbothermal reduction reaction is a two-step process, as was confirmed by X-ray diffraction and previously described by Baca et al [22]:…”

Section: Tib 2 Support Materialssupporting

confidence: 60%

Importance of Fuel Cell Tests for Stability Assessment—Suitability of Titanium Diboride as an Alternative Support Material

et al. 2014

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“…Consequently, a lowertemperature route for preparing TiB 2 is imperatively needed. In the last year (2008) two different methods for the preparation of TiB 2 powders were reported, but both were performed at temperatures up to 1400 • C [14,15].…”

Section: Introductionmentioning

confidence: 99%

Sn-flux syntheses, characterizations and bonding analyses of OsB and TiB2

Fokwa

Misse

Gilleßen

et al. 2010

Journal of Alloys and Compounds

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“…The detailed procedure of precursor preparation is described elsewhere. 16 Briefly, the starting boron oxide and strontium nitrate were dissolved in water, whereas titanium tetrachloride was slowly added to the calculated amount of ethylene glycol. Both solutions were mixed together and ethylene glycol was added in CA:EG ratio of 2:3, to promote the polymerization during the evaporation of water.…”

Section: Methodsmentioning

confidence: 99%

“…Based on the previous XRD and Raman results in Ti-B-C-O system, 16 where the annealing of precursors at 1100 • C shows only the formation of TiBO 3 , rutile and graphite, thus the starting temperature of 1200 • C was selected for the first calcination of Sr-doped precursor. DTA-TG spectra of 1200 • C treated sample (STB-10, Table 1) were recorded up to 1600 • C in order to study the processes at higher temperatures.…”

Section: Dta-tg and Xrd Analysismentioning

confidence: 99%