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The Pt-chitosan-TiO

The detailed reaction mechanism with microstructural changes of iron ore fines in H2 atmosphere has been investigated using a high temperature drop tube furnace. With the model free method, the activation energy of 281 kJ/mol was obtained, indicating that solid-state diffusion of ions in lattice matrix of iron ore particle was the rate-controlling step. The analysis was therefore extended to obtain the microstructural information of the reduction product. It is found that dense product layers were formed and solid-state diffusion of iron and oxygen ions played a key role in the reduction process. The structure evolution of iron ore particles during the transformation from hematite to magnetite is the same as that from magnetite to wustite, while the transformation from wustite to metallic iron is clearly different. The microstructural changes and the elementary reaction steps during the two types of transformation are obtained and characterized.

A series of nitrogen-doped CoAlO (N-CoAlO) were constructed by a hydrothermal route combined with a controllable NH

Unsatisfactory oxygen mobility is a considerable barrier to the development of perovskites for low-temperature volatile organic compounds (VOCs) oxidation. This work introduced small amounts of dispersed non-metal boron into the LaCoO

A one-dimensional (1D) core-shell of Co-Ce oxide has been prepared by multifluidic coaxial electrospinning method and evaluated for the total oxidation of propane (C

The properties of LaCoO

The electrochemical CO2 reduction reaction (ECO2RR) on Cu catalysts affords high‐value‐added products and is therefore of great practical significance. The outcome and kinetics of ECO2RR remain insufficient, requiring essentially the optimized structure design for the employed Cu catalyst, and also the fine synthesis controls. Herein, synthesis‐controlled structure preferences and the modulation of intermediate's interactions are considered to provide synthesis‐related insights on the design of Cu catalysts for selective ECO2RR. First, the origin of ECO2RR intermediate‐dominated selectivity is described. Advanced structural engineering approaches, involving alloy/compound formation, doping/defect introduction, and the use of specific crystal facets/amorphization, heterostructures, single‐atom catalysts, surface modification, and nano‐/microstructures, are then reviewed. In particular, these structural engineering approaches are discussed in association with diversified synthesis controls, and the modulation of intermediate generation, adsorption, reaction, and additional effects. The results pertaining to synthetic methodology‐controlled structural preferences and the correspondingly motivated selectivity are further summarized. Finally, the current opportunities and challenges of Cu catalyst fabrication for highly selective ECO2RR are discussed., This review summarizes the synthesis methodology‐controlled structure preference, and the structure engineering‐modulated intermediate generation, stabilization, and reaction on Cu‐based catalysts, toward highly selective electrochemical CO2 reduction to the products as‐desired.

A new versatile method was developed for the synthesis of various transition metal oxides with uniform 1D structures via electrospinning combined with heat treatment. The 1D nanowire or hollow tubular structure can be tuned by controlling heating rates. Interestingly, NOx conversion is ca. 99% at 200 °C in hollow tubular CuCo2O4.

The objective of this work was to develop a novel organic-inorganic hybrid nanomaterial from agricultural biomass waste for environmental applications. The sugarcane bagasse (SB) supported TiO

A new versatile method was developed for the synthesis of various transition metal oxides with uniform 1D structures via electrospinning combined with heat treatment. The 1D nanowire or hollow tubular structure can be tuned by controlling heating rates. Interestingly, NO

High thermally stable mesoporous alumina doped with lanthanum was synthesized using inorganic nitrates as precursors and employing pluronic P123 (P123, (EO20PO70EO20, EO=ethylene oxide, PO=propylene oxide)) as a structure-directing agent. After calcination at 400 °C, the resultant lanthanum doped alumina exhibited a γ-Al2O3 phase, which was the same as pure alumina. After the thermal treatment up to 1200 °C, La-doped Al2O3 generated only one phase of θ-Al2O3 rather than two mixed phase of θ-Al2O3 and α-Al2O3 and the surface area could still maintain 101 m2/g with a keeping pore volume of 0.66 cm3/g. The excellent thermal stability was explained by the titration of strong Lewis acid sites of γ-Al2O3 with the assistance of highly dispersed lanthanum species covering on alumina. Furthermore, the lanthanum modified mesoporous alumina was preliminarily employed as a stable support for Pd in the catalytic oxidation of C3H8.

Three different techniques, a hydrothermal process with impregnation, solution-combustion and common precipitation with impregnation, were employed for the synthesis of 1.5 wt% Pd/CeO 2 , and the resulting catalysts were denoted as Pd/HY, Pd/COM and Pd/PI, respectively. These catalysts have been investigated in terms of catalytic co-oxidation of CO and methanol and characterized by means of XRD, BET, SEM, STEM-EDS, CO chemisorption, XPS, Raman, O 2 -TPD, H 2 -TPR and CO-TPD measurements. Activity results show that a rapid catalytic oxidation of CO following the Mars-van Krevelen-type mechanism favors the complete methanol oxidation at low temperature. Consequently, the Pd/HY catalyst with the highest degree of defect sites connected with the mobility of activated oxygen shows the best catalytic performance. And the generation of more defect sites demonstrated by Raman is assumed for the low crystallinity and small crystallite size of CeO 2 synthesized through a hydrothermal process while the high mobility of activated oxygen is evidenced by O 2 -TPD and H 2 -TPR. Additionally, the outstanding catalytic performance of Pd/HY is also associated with its high Pd dispersion and stable PdO x species as well as good redox behavior.

Al2O3-Ce0.3Zr0.7O2 and 3 wt% BaO doped Al2O3-Ce0.3Zr0.7O2 were prepared by coprecipitation and the supported 0.25 wt% Pd catalysts were compared in the complete oxidation of methanol. The work dealt with a combined investigation of the effect of adding barium on the characteristics of the catalyst and on its catalytic performance of methanol oxidation. The results demonstrate that more active sites at low temperature and more basic sites needed for deep oxidation of methanol are formed after doping barium.

A series of bimetallic Pd/Ag/γ-Al 2 O 3 modified by various contents (15, 25, 35, 50, and 65 wt.%) of Ce 0.25 Zr 0.75 O 2 were prepared and used as catalysts for the oxidation reaction of CH 3 OH. The reaction results indicate that addition of Ce 0.25 Zr 0.75 O 2 could decrease the light-off temperature of methanol conversion. Samples with 35, 50 and 65 wt.% of Ce 0.25 Zr 0.75 O 2 show markedly enhanced activity attaining the light-off temperature near 85 °C, which may resolve the complete oxidation reaction of methanol at low temperature.

Cu/Ba/bauxite possesses superior NOx storage and reduction (NSR) performances, high thermal stability, strong resistance against SO2 poisoning and outstanding regeneration ability in comparison with Pt/Ba/Al2O3. It can serve as a cheap and promising alternative for traditional Pt/Ba/Al2O3 in NOx removal from lean-burn engines.

The aim of software testing is to find faults in the program under test. Previous methods of path-oriented test data generation can generate test data traversing target paths, but they may not guarantee to find faults in the program. We present a method of evolutionary generation of test data for path coverage with faults detection in this paper. First, we establish a mathematical model of the problem considered in this paper, in which the number of faults detected in the path traversed by test data, and the risk level of faults are optimization objectives, and the approach level of the traversed path from the target one is a constraint. Then, we generate test data using a multi-objective evolutionary optimization algorithm with constraints. Finally, we apply the proposed method in a benchmark program bubble sort and an industrial program totinfo, and compare it with the traditional method. The experimental results conform that our method can generate test data that not only traverse the target path but also detect faults in it. Our achievement provides a novel way to generate test data for path coverage with faults detection.

We report an interesting finding that the catalytic performance of Pd/Al2O3-Ce0.6Zr0.4O2 catalyst toward complete oxidation of methanol at low temperature could be greatly enhanced by prereduction in hydrogen. The light-off temperature (T50) could be reached rapidly at 67 °C. TPR patterns showed that the reducibility is highly increased due to the formation of stronger interactions between PdOx and CeO2 after hydrogen pretreatment. It was confirmed by XPS analysis, and the generation of higher charged Pdδ+ (δ > 2) species were discovered. As a result, it was induced that the presence of stronger interactions between PdOx and CeO2 after prereduction mainly contributes to the remarkably enhanced activity.