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Abstract: The current study describes the catalytic ozonation of toluene using MCM-41 catalysts modified by different transition metals (Cu and Co) and methods (in situ synthesis and impregnation). The characteristic hexagonal channel array of the MCM-41 pore system was not destroyed by the transition metal modification, but the order and surface area were decreased. Large particles of copper oxide exposed on the (111) lattice plane, which were indicative of severe sintering, were found on the catalyst modified by Cu via in situ synthesis. Such particles were not observed on the other catalysts. Using the modified catalysts in toluene ozonation revealed that with increased reaction temperature, toluene conversion under a steady state increased, whereas ozone conversion decreased. The transition metal-modified MCM-41s also had largely improved catalytic activities compared with pure MCM-41. Catalytic performance was found to depend on the metal type and modification method. The method that resulted in improved catalytic performance was in situ synthesis for the Co-modified MCM-41, and was impregnation for the Cu-modified MCM-41. The relatively superior performance of the transition metal-modified catalysts over pure MCM-41 is attributed to two main features. One is the well dispersion of metal oxides, and the other is the strong capacity to decompose built-up organic byproducts on the catalyst surface. [Copyright &y& Elsevier]

A novel porous copper fiber sintered felt (PCFSF) as catalyst support is fabricated to construct the methanol steam reforming microreactor for hydrogen production. In this study, the heat and mass transfer properties of PCFSF with different porosities is experimentally investigated. The results show that the PCFSF with different porosities exhibits good uniform heat transfer. The thermal conductivity is decreased with increasing porosity in the porosity range of 70–90%. With lower gas feed rate, no great change of the pressure drop is observed. However, larger pressure drop is produced with the higher gas feed rates. Moreover, we found that the resident time in the PCFSF is gradually decreased with increasing porosity. Much longer resident time is obtained when the lower gas feed rate is selected. The PCFSF with 80% porosity as catalyst support presents better reaction performance because of the enhancement of heat and mass transfer resulting from the unique porous structure. [ABSTRACT FROM AUTHOR]

Highlights: [•] Both three- and four-point bending setup were established. [•] Similar three stages in three- and four-point bending fracture process were observed. [•] The bending strength was decreased with increasing porosity. [•] Higher sintering temperature produced higher bending strength. [•] The extension of holding time slightly affected the bending strength. [Copyright &y& Elsevier]

Abstract: A novel porous metal fiber sintered sheet (PMFSS) with high porosity was fabricated by the solid-state sintering method of copper fibers. In this study, the shear experiments were conducted to investigate the effect of porosity and sintering parameter on the shear properties of PMFSS. The typical shear stress–strain plot of PMFSS was obtained based on a larger number of shear test results. The shear fracture process of PMFSS was then divided into three steps: linear elastic stage, plastic deformation stage, and shear fracture stage. The shear strength was found to be decreased with increasing porosity ranging from 70% to 90% when the PMFSS was produced under the same sintering parameter. Moreover, the influence of sintering parameter on shear strength of PMFSS was also investigated. Our experimental results showed that the increase of the sintering temperature or holding time would give rise to the increase of shear strength of PMFSS. [Copyright &y& Elsevier]

Abstract: Novel porous metal fiber sintered sheets (PMFSSs) with different porosities were fabricated by sintering copper fibers. Using four-point probe method, comparative study was conducted to investigate the effects of probe spacing, porosity, and sintering condition on the electrical conductivity of PMFSS. Our experimental results showed that probe spacing plays an important role in determining the electrical conductivity. Uniform probe spacing was adopted in order to reduce the error caused by non-uniformity of probe spacing. The measured electrical conductivity was found to decrease with increasing porosity ranging from 70% to 90% for the PMFSS produced under the same sintering condition. Our experimental results were found to agree well with the theoretical prediction by Liu’s model for the PMFSS with different porosities. The effect of sintering condition on electrical conductivity was also investigated. It was revealed that higher sintering temperature or longer holding time yields higher electrical conductivity of PMFSS. [Copyright &y& Elsevier]

Abstract: A novel porous metal fiber sintered sheet (PMFSS) with three-dimensional reticulated structure was fabricated by using solid-state sintering method of copper fibers. Uniaxial compressive test was carried out to investigate the effects of porosity and manufacturing parameters on the compressive properties of PMFSS. During the compressive process, it was found that the PMFSS initially exhibited short-term elastic deformation, and then quickly entered into the compact densification deformation stage. The stress–strain plots showed no obvious yield stage in the whole uniaxial compressive process. Under given stress, the PMFSS with higher porosity exhibited higher strain, hence implying lower effective stiffness. Additionally, our results showed that higher sintering temperature or longer sintering time would soften the PMFSS. [Copyright &y& Elsevier]