Perovskite solid solutions are screened both experimentally and through DFT to determine their redox properties for thermochemical applications.

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The preparation and the thorough characterization of 40 wt% Pt electrocatalysts supported on Ti (1-x) M x O 2-C (M= W, Mo; x= 0.3-0.4) composite materials with enhanced stability and efficiency is presented. W-containing composite supported catalyst with different structural characteristics were compared in order to explore the influence of the nature of the W species on the electrocatalytic performance. The assessment of the electrochemical properties of the novel catalysts revealed a correlation between the degree of W incorporation, the hydrogen spillover effect and the stability against initial leaching which influences the activity and CO tolerance of the catalysts. A preparation route for Ti 0.7 Mo 0.3 O 2-C composite with high extent of Mo incorporation was developed. No significant difference was observed in the activity, stability and CO tolerance of the W-or Mo-containing composite supported Pt catalysts with almost complete incorporation of the oxophilic dopant. Better performance of the Pt/Ti 0.7 M 0.3 O 2-C (M= W, Mo) electrocatalysts in a single cell test device using hydrogen containing 100 ppm CO compared to the reference Pt/C and PtRu/C (Quintech) catalysts was also demonstrated.

Ti-based electroconductive mixed oxides were deposited onto activated carbon by using three different sol-gel-based multistep synthesis routes. As demonstrated by X-ray diffraction, high crystallinity of the tungsten-loaded rutile was achieved by a sequence of annealing in inert atmosphere at 750°C and a short reductive treatment at 650°C.Formation of the rutile phase on the carbon support before the high temperature treatment has been proved to be the prerequisite for complete W incorporation into the rutile lattice. The structural and compositional properties of the mixed oxides were explored by transmission electron microscopy, temperature programmed reduction and X-ray photoelectron spectroscopy. Anode electrocatalysts were formulated by loading the composite of the activated carbon and the Ti-based electroconductive mixed oxides with 40 wt% Pt. Enhanced CO tolerance along with considerable stability was demonstrated for the electrocatalyst prepared using the Ti 0.7 W 0.3 O 2 -C composite material with high degree of W incorporation.

an increase of the activity in both electrooxidation reactions as a consequence of an optimal balance of Pt/Sn ratio, the content of fcc Pt 3 Sn phase and metal particle size. It was demonstrated that the increasing tin content above a certain (optimal) amount gives rise to a negative effect on the catalyst performance in the CO and methanol electrooxidation.

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