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Nanosized Fe3+ and Eu3+ codoped CeO2 solid solutions were synthesized via hydrothermal method. The crystalline structure of Ce1−x(Fe0.5Eu0.5)xO2−δ (x=0.00–0.30) solid solutions was carried out by the X–ray diffraction technique, and the spectrum features were identified by UV–Vis and Raman spectroscopy, respectively. It was observed that the cell parameters were first increased then decreased by increasing the doped ions content. The phase separation was detected when the dopant concentration reached to x=0.30. UV–Vis spectrum showed that the width of the band gap gradually reduced by increasing the doped content, and the solid solubility was determined to be x=0.20. The Raman technique displayed that the peak position of F2g mode gradually shifted to lower frequencies from 465 cm−1 for x=0.00 to 440 cm−1 for x=0.20. The catalytic effects of Ce1−x(Fe0.5Eu0.5)xO2−δ solid solutions on the electrochemistry properties of Mg2Ni/Ni were measured by mixing them together via ball milling technique. The electrochemical properties of the Mg2Ni/Ni–Ce1–x(Fe0.5Eu0.5)xO2−δ composites showed that the maximum discharge capability Cmax and the cycle stability were improved obviously. Meanwhile, the EIS characteristic also indicated that the doped solid solutions could enhance the rate of charge transfer on the surface of alloy. The catalytic effect of the solid solutions was speculated to rely on both the concentration of oxygen vacancies and the cell volumes of the solid solutions.

The electrocatalytic activity and stability of Pt/C catalyst modified by using CeO2-ZrO2 mixed oxides for the alcohols electrochemical oxidation as probes were investigated. The catalyst samples were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The electrochemical properties were measured by a three electrode system on electrochemical workstation (IVIUM). The results showed that the presence of CeO2-ZrO2 might be associated with the presence of Pt, which indicated that possibly there was synergistic effect between CeO2-ZrO2 and Pt nanoparticles. The electrocatalytic activity and stability of Pt-MOx/C (M=Ce, Zr) for methanol and ethanol oxidation was better than that of Pt-CeO2/C, which was attributed to that CeO2-ZrO2 composited oxides enhanced oxygen mobility and promoted oxygen storage capacity (OSC). Furthermore, the best performance was found when the molar ratio of CeO2 to ZrO2 was 2:1 for the oxidation of methanol and ethanol. The forward peak current density of Pt-MOx/C (M=Ce, Zr, Ce:Zr=2:1) towards the methanol electrooxidation was about 3.8 times that of Pt-CeO2/C. Pt-MOx/C (M=Ce, Zr) appeared to be a promising and less expensive methanol oxidation anode catalyst.

In order to improve the hydrogenation and dehydrogenation performances of the Mg 2 Ni-type alloys, Mg was partially substituted by La in the alloy, and melt spinning technology was used for the preparation of the Mg 20– x La x Ni 10 ( x =0, 2, 4, 6) hydrogen storage alloys. The structures of the alloys were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM). It was found that no amorphous phase formed in the as-spun La-free alloy, but the as-spun alloys containing La held a major amorphous phase. When La content x ≤2, the major phase in the as-cast alloys was Mg 2 Ni phase, but with further increase of La content, the major phase of the as-cast alloys changed into LaNi 5 +LaMg 3 phase. Thermal stability of the as-spun alloys was studied by differential scanning calorimetry (DSC), showing that spinning rate was a negligible factor on the crystallization temperature of the amorphous phase. The hydrogen absorption and desorption kinetics of the as-cast and as-spun alloys were measured using an automatically controlled Sieverts apparatus, confirming that the hydrogen absorption and desorption capacities and kinetics of the as-cast alloys clearly increased with rising La content. For La content x =2, the as-spun alloy displayed optimal hydrogen desorption kinetics at 200 °C.