Ethanol electro-oxidation activity of Nb-doped-TiO2 supported PdAg catalysts in alkaline media

Various mesoporous Nb-doped titania materials were synthesized by a hydrothermal method and examined as catalyst support for PdAg alloy particles for alkaline direct ethanol fuel cell (ADEFC). X-ray diffraction, nitrogen adsorption/desorption, transmission electron microscopy (TEM), cyclic voltammetry (CV) and chronoamperometry (CA) were used to investigate the properties of the supports and catalysts. 700 °C was found as the optimal activation temperature for Nb-doped TiO2 due to the high electronic conductivity achievement and mesoporosity conservation. X-ray diffraction (XRD) revealed that NbxTi1−xO2 had a structure of mixed anatase and rutile phases. PdAg/NbxTi1−xO2 exhibited excellent performance for the electrooxidation of ethanol and higher durability in alkaline solution compared with PdAg/C and PdAg/commercial TiO2. The results open a new way to develop durable and effective electrocatalysts for ADEFC.

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► Mesoporous Nb-doped titania materials, NbxTi1−xO2, were synthesized.
► The effect of Nb ratio and synthesis temperature on the conductivity of Nb-doped TiO2 was examined.
► Much improved durability in alkaline media was observed for NbxTi1−xO2.
► PdAg/NbxTi1−xO2 shows improved activity and stability towards ethanol oxidation compared with carbon black and titania.