Vanadium Doped TiO 2 As a Novel Support Material for Anode Electro Catalyst in Polymer Electrolyte Membrane Water Electrolysers

Content Provider	Semantic Scholar
Copyright Year	2013
Abstract	Growing concerns about global warming and energy security demand the expansion of renewable energy sources as viable alternatives to fossil-fuel-based technologies, in conjunction with improved energy storage options. In many of the innovative approach es to address these challenges, the production of hydroge n in various (photo)-electrolysis systems plays a pivota l role. To produce hydrogen using renewable energies, water electrolysis is a fundamental and flexible approach because of its compatibility with all types of elec tricity generation[1]. The state-of-the-art technology of w ater electrolysis is based on a solid polymer electrolyt e(SPE). In comparison to the traditional device using alkal ine solutions, SPE water electrolysis is more efficient in energy conversion and safer in application. However , th major drawback of the SPE is the need for electro catalysts based on platinum group metals. This espe cially concerns the anode, where so far only iridium based electro catalysts are known to withstand the severe conditions that occur at the anode during the oxyge n evolution reaction (OER) [2]. Unfortunately, iridiu m is not only expensive, but also scarce, being about 50 times less abundant than platinum. Consequently, it is cr ucial to reduce the amount of IrO 2 in polymer electrolyte membrane water electrolysers if this technology is to become more widely used. One method is to disperse the precious metal nanoparticles on a support in order to maximize the specific surface area and enhance the specific mass activity of the catalysts. In the present work, we report a novel support material for anode electro catalyst in SPE. Althoug h it’s bed electrical conductivity, TiO 2 is interesting to evaluate as catalyst support material due to its high stabil i y at high potential in hydrous, acidic environment. So vanadi um element is doped in TiO 2, which can introduce defects to give the non-stoichiometric oxide compositions Ti (1x)VxO2+δ. The oxide compositions will exhibit a high electrical conductivity at room temperature. Furthe r more, Mesoporous vanadium doped TiO 2 supports were prepared through modified Evaporation-Induced SelfAssembly (EISA)[3], which the specific surface area can be achieved at 137 m /g. The electro catalysts with varying content of IrO2 were prepared, using a modified version of the Adams fusion method. The X-ray diffraction (XRD) patterns of the synthesized electro catalysts samples are depicted in Fig.1. The samples TiO2 and Ti 70V30O2+δ, which were prepared by EISA and Adams fusion method, show a mixed phas e with predominantly anatase phase peaks comparable w ith rutile phase. The small shift observed in the XRD p eaks comparable with TiO2 and Ti 70V30O2, which may be attributed to the incorporation of V inside the tit ania lattice. No other peaks from possible impurities/su rface vanadium are detected. The cyclic voltammograms of the IrO 2-based electro catalysts has been shown in Fig.2. A reliable, gene rally accepted electrochemical method of determining the active area, as it has for example been established for platinum, has not yet been found for iridium oxide. In the potential region between 0.5 and 1.5 V, the anodic and cathodic parts of the voltammograms for IrO 2 display a high degree of symmetry. The predominant influence of IrO2 on the voltammetric response of the electrode is indicated by the anodic-to-cathodic charge ratio (Q a/Qc) being close to unity. However, a low degree of symm etry are displayed for the support loading 40wt.% IrO 2 and 20wt.% IrO2. They are in agreement with the work of Polonsky et al. [4], who observed that the charge r atios of the electro catalysts increased when the content of the IrO2 was reduced below 50 wt.%. These results indicate enhanced interaction of the support with the electr olyte. The CV of 40IrO2/Ti70V30O2+δ shows larger active area than IrO2 and 40IrO2/TiO2. The present results demonstrate that Ti 70V30O2+δ may be a potential support for anode electro catalyst in SPE.
Starting Page	1527
Ending Page	1527
Page Count	1
File Format	PDF HTM / HTML
DOI	10.1149/ma2013-02/15/1527
Alternate Webpage(s)	https://ecs.confex.com/ecs/224/webprogram/Abstract/Paper24401/B11-1527.pdf
Alternate Webpage(s)	https://doi.org/10.1149/ma2013-02%2F15%2F1527
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article