Nanosized rod-like, wire-like, and tubular α-MnO(2) and flower-like spherical Mn(2)O(3) have been prepared via the hydrothermal method and the CCl(4) solution method, respectively. The physicochemical properties of the materials were characterized using numerous analytical techniques. The catalytic activities of the catalysts were evaluated for toluene oxidation. It is shown that α-MnO(2) nanorods, nanowires, and nanotubes with a surface area of 45-83 m(2)/g were tetragonal in crystal structure, whereas flower-like spherical Mn(2)O(3) with a surface area of 162 m(2)/g was of cubic crystal structure. There were the presence of surface Mn ions in multiple oxidation states (e.g., Mn(3+), Mn(4+), or even Mn(2+)) and the formation of surface oxygen vacancies. The oxygen adspecies concentration and low-temperature reducibility decreased in the order of rod-like α-MnO(2) > tube-like α-MnO(2) > flower-like Mn(2)O(3) > wire-like α-MnO(2), in good agreement with the sequence of the catalytic performance of these samples. The best-performing rod-like α-MnO(2) catalyst could effectively catalyze the total oxidation of toluene at lower temperatures (T(50%) = 210 °C and T(90%) = 225 °C at space velocity = 20,000 mL/(g h)). It is concluded that the excellent catalytic performance of α-MnO(2) nanorods might be associated with the high oxygen adspecies concentration and good low-temperature reducibility. We are sure that such one-dimensional well-defined morphological manganese oxides are promising materials for the catalytic elimination of air pollutants.

The real capacity of graphene and the lithium-storage process in graphite are two currently perplexing problems in the field of lithium ion batteries. Here we demonstrate a three-dimensional bilayer graphene foam with few defects and a predominant Bernal stacking configuration, and systematically investigate its lithium-storage capacity, process, kinetics, and resistances. We clarify that lithium atoms can be stored only in the graphene interlayer and propose the first ever planar lithium-intercalation model for graphenic carbons. Corroborated by theoretical calculations, various physiochemical characterizations of the staged lithium bilayer graphene products further reveal the regular lithium-intercalation phenomena and thus fully illustrate this elementary lithium storage pattern of two-dimension. These findings not only make the commercial graphite the first electrode with clear lithium-storage process, but also guide the development of graphene materials in lithium ion batteries.

Three-dimensionally ordered macro/mesoporous Ce 0.6 Zr 0.3 Y 0.1 O 2 (3DOM CZY) supported high-dispersion Pt nanoparticles (x wt % Pt/3DOM CZY, x = 0.6, 1.1, and 1.7) were successfully synthesized via the cetyltrimethylammonium bromide/triblock copolymer P123 assisted gas bubbling reduction route. The 3DOM CZY and x wt % Pt/3DOM CZY samples exhibited a high surface area of 84−94 m 2 /g. Pt nanoparticles (NPs) with a size of 2.6−4.2 nm were uniformly dispersed on the surface of 3DOM CZY. The 1.1 wt % Pt/3DOM CZY sample showed excellent catalytic performance, giving a T 90% value at 598 °C at gas hourly space velocity (GHSV) of 30000 mL/(g h) and the highest turnover frequency (TOF Pt ) of 6.98 × 10 −3 mol/(mol Pt s) at 400 °C for methane combustion. The apparent activation energy (64 kJ/mol) over 1.1 wt % Pt/3DOM CZY was much lower than that (95 kJ/mol) over Bulk CZY. The effects of water vapor and SO 2 on the catalytic activity of 1.1 wt % Pt/3DOM CZY were also examined. It is concluded that the excellent catalytic activity of 1.1 wt % Pt/3DOM CZY was associated with its high oxygen adspecies concentration, good lowtemperature reducibility, and strong interaction between Pt NPs and CZY as well as large surface area and unique nanovoidwalled 3DOM structure.

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