The performance of a low temperature fuel cell is strongly correlated with parameters like the platinum particle size, platinum dispersion on the carbon support, and electronic and protonic conductivity in the catalyst layer as well as its porosity. These parameters can be controlled by a rational choice of the appropriate catalyst synthesis and carbon support. Only recently, particular attention has been given to the support morphology, as it plays an important role for the formation of the electrode structure. Due to their significantly different structure, mesoporous carbon microbeads (MCMBs) and multiwalled carbon nanotubes (MWCNTs) were used as supports and compared. Pt nanoparticles were decorated on these supports using the polyol method. Their size was varied by different heating times during the synthesis, and XRD, TEM, SEM, CV, and single cell tests used in their detailed characterization. A membrane-electrode assembly prepared with the MCMB did not show any activity in the fuel cell test, although the catalyst's electrochemical activity was almost similar to the MWCNT. This is assumed to be due to the very dense electrode structure formed by this support material, which does not allow for sufficient mass transport.

La1−xCexCoO3(x= 0, 0.2, 0.4) and La1−xCexMnO3(x= 0, 0.2) perovskite-type oxides were prepared by sol-gel process. Characterization techniques EDS, FTIR, XRD, BET, and XPS experiments were performed to survey the composition, bulk structure, and the surface properties of perovskites. The reduction behavior, thermal stability, and catalytic activity were studied by H2-TPR and catalytic performance. All synthesized samples showed well crystalline perovskite structure, 8–22 nm crystallite sizes, and SSA with 2–27 m2 g−1. The XRD results showed that the Ce substitution promoted the structural transformation for LaCoO3from rhombohedral into cubic and for LaMnO3no change in lattice geometry. Substitution with cerium (x= 0.2) showed smaller crystallite size, higher SSA, and the highest reducibility and catalytic activity for LaCoO3.

Nanosized spinel Li4Ti5O12 was successfully synthesized by a solid state reaction method at 800°C according to the Li4Ti5O12cubic spinel phase structure. In this synthesizing process, anatase TiO2and Li2CO3were used as reactants. The average grain size of the synthesized powders was around 200 nm. The synthesized Li4Ti5O12powder was characterized X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray spectrometry (EDS), and Specific Surface Area Analyzer (BET, Brunner-Emmett-Teller) respectively. X-ray diffraction results show that calcination temperature and time have the important effects on the crystal structure of Li4Ti5O12powder. In this study, we used a first principle method, based on the density functional theory to explore electronic and structural properties of Li4Ti5O12, as anode material for lithium ion batteries. Differences on these properties between delithiation state Li4Ti5O12and lithiation state Li7Ti5O12are compared. All the predicted structural and electrochemical properties agree closely with the experimental findings in literature. The average intercalation voltage of 1.4V during charging/discharging were obtained. We have shown that the Li4Ti5O12material exhibits insulating behavior with the band gap of 3.16 and 3.90 eV using the GGA and GGA+U+J0calculations respectively. Li7Ti5O12becomes metallic as Li atoms inserted in Li4Ti5O12material. Spinel Li4Ti5O12has been regarded as an attractive anode material for the development of high-power lithium-ion batteries because of its unique attributes of high safety and rate capability.