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Two-dimensional nanostructures have been rarely reported as thermally stable catalysts for heterocatalysis. In this work, CeO 2 nanoparticle-modified Co 3 O 4 nanosheets were successfully obtained via a wet-chemistry process in water phase and a following in-situ solvent-free heat treatment in the presence of 1,4-benzenedicarboxylic acid. Detailed characterizations have been conducted to disclose the structural evolution of the Co 3 O 4 nanosheets as well as the synergistic effect between Co 3 O 4 and CeO 2 components. Also, it is identified that CeO 2 played the important role in stabilizing Co 3 O 4 nanosheets, and 1,4-benzenedicarboxylic acid greatly improved the smoothness of the final products. Such two-dimensional structural formation boosts the performance of the as-prepared Co 3 O 4 nanosheets toward the model reaction of catalytic CO oxidation. More importantly, this work presents us an effective way to prepare transition metal oxides from the viewpoint of structural design of two-dimensional materials.

In order to improve the accuracy of numerical simulation, a new heat transfer model is developed by using a modular approach in the Anstalt für Verbrennungskraftmaschinen (AVL)-Boost software. The improved heat transfer model mainly considers the effects of the swirl and boiling heat transfer inside the engine. In addition, a chemical kinetics mechanism including 475 reactions and 134 species is employed to predict the combustion of diesel engines fueled with biodiesel. The result shows that the boiling heat transfer will occur, especially in the high-temperature area. Analysis shows that the improved model is reliable and its precision is increased. Finally, the perturbation method is employed to investigate the relatively important inputs as the complex nonlinear function with a lot of output data and input data produced by the improved model. The relative effects of different parameters such as EGR, injection mass, injection timing, compression ratio, inlet air pressure, fuel injection pressure, exhaust pressure and inlet air temperature on performance and emission characteristics are compared. The eight parameters are investigated on four outputs of brake power, Brake Specific Fuel Consumption (BSFC), NOx and HC. The injected fuel mass plays an important role in emissions and performance. The EGR, compression ratio and inlet air pressure have a great effect on the HC and NOx emission.

To fabricate functionally integrated hybrid nanoparticles holds high importance in biomedical applications and is still a challenging task. In this study, we report the first reduced graphene oxide (rGO)-nobel metal hybrid particles that present simultaneously the photothermal and surface-enhanced Raman spectroscopy (SERS) effect from the inorganic part and drug loading, dispersibility, and controllability features from LbL polyelectrolyte multilayers. The hybrid particles where spiky noble metal particles were wrapped within rGO-polyelectrolyte layers were prepared by a facile and controllable method. rGO template modified using polyethylenimine (PEI) and poly(acrylic acid) (PAA) via layer-by-layer technology served as the reactive precursors, and the morphologies of the particles could be facilely controlled via controlling the number of bilayers around the rGO template. The hybrid particle presented low cytotoxicity. After loading doxorubicin hydrochloride, the particles effectively induced cell death, and photothermal treatment further decreased cell viability. rGO-Ag hybrid particles could be prepared similarly. We expect the reported method provides an effective strategy to prepare rGO-noble metal hybrid nanoparticles that find potential biomedical applications.

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Pd@CeO /Al O catalysts are of great importance for real applications, such as three-way catalysis, CO oxidation, and methane combustion. In this article, the Pd@CeO core@shell nanospheres are prepared via the autoredox reaction in aqueous phase. Three kinds of methods are then employed, that is, electrostatic interaction, supramolecular self-assembly, and physical mixing, to support the as-prepared Pd@CeO nanospheres on γ-Al O . A model reaction of catalytic methane-combustion is employed here to evaluate the three Pd@CeO /γ-Al O samples. As a result, the sample Pd@CeO -S-850 prepared via supramolecular self-assembly and calcined at 850 °C exhibits superior catalytic performance to the others, which has a far lower light-off temperature (T of about 364 °C). Moreover, almost no deterioration of Pd@CeO -S-850 is observed after five sequent catalytic cycles. The analysis of H -TPR curves concludes that there exists hydrogen spillover related to the strong metal-support interaction between Pd species and oxides. The strong metal-support interaction and the specific surface areas might be responsible for the catalytic performance of the Pd@CeO samples toward catalytic methane combustion.

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