1,720,987 research outputs found
A study on residual stress reduction in ceramic/metal brazed joints by using copressive loads
No full textHighly Selective Transformation of Glycerol to Dihydroxyacetone without Using Oxidants by a PtSb/C-Catalyzed Electrooxidation Process
No full textWe demonstrate an electrocatalytic reactor system for the partial oxidation of glycerol in an acidic solution to produce value-added chemicals, such as dihydroxyacetone (DHA), glyceraldehyde (GAD), glyceric acid (GLA), and glycolic acid (GCA). Under optimized conditions, the carbon-supported bimetallic PtSb (PtSb/C) catalyst was identified as a highly active catalyst for the selective oxidation of glycerol in the electrocatalytic reactor. The product selectivity can be strongly controlled as a function of the applied electrode potential and the catalyst surface composition. The main product from the electrocatalytic oxidation of glycerol was DHA, with a yield of 61.4% of DHA at a glycerol conversion of 90.3%, which can be achieved even without using any oxidants over the PtSb/C catalyst at 0.797 V (vs. SHE, standard hydrogen electrode). The electrocatalytic oxidation of biomass-derived glycerol represents a promising method of chemical transformation to produce value-added molecules.111810sciescopu
Unveiling the enhanced electrocatalytic activity at electrochemically synthesized Pt-WOxhybrid nanostructure interfaces
No full textHere we report a simple synthesis strategy for Pt-WOxhybrid nanostructures using a metal-dissolution-based electrodeposition technique. The hybrid nanostructures demonstrate an excellent catalytic hydrogen evolution reaction performance with an approximately 17 times higher Pt mass activity and a 7.4 times higher turnover frequency than those of commercial Pt catalysts. The enhanced electrocatalytic performance is related to the creation of Pt-WOxinterfacial sites. ? The Royal Society of Chemistry 2021.11Nsciescopu
Catalytic complete oxidation of 1,2-dichloroethane over Al-Ti mixed oxide supported VOx catalyst
No full textChlorinated volatile organic compounds (CVOCs) are of hazardous atmospheric contaminants that can cause substantial harmful effects on human and environment. Herein, highly active composite catalysts of VOx supported on Al-Ti mixed oxide were prepared by a sol-gel process followed by a wet-impregnation method, and they were investigated for catalytic combustion of 1,2-dichloroethane (DCE) as representative CVOCs. The VOx/Al-Ti mixed oxide composite catalysts showed the highly active and stable performance toward the catalytic oxidation of DCE, as compared with the corresponding single metal oxides or Al-Ti mixed oxides. Considering the characterization analysis combined with the catalytic performance results, both acidic property of Al-Ti mixed oxides and redox feature of VOx catalysts seem to play critical roles in the complete oxidation of 1,2-dichlomethane. The strategy of catalyst design developed in this work may provide the way for exploitation of earthabundant, nonprecious and efficient composite catalysts for catalytic CVOCs removal processes.11Nsciescopu
Mesoporous carbon host material for stable lithium metal anode
No full textLithium (Li) metal is a promising anode material for next-generation batteries because of its low standard reduction potential (-3.04 V vs. SHE) and high specific capacity (3860 mA h g-1). However, it is still challenging to directly use Li metal as anode material in commercial batteries because of unstable Li dendrite formation and accumulated solid-electrolyte interphase. Possible methods that can suppress the unwanted formation of Li dendrites are (i) by increasing the electrode surface area and (ii) formation of porosity for confining Li. Here, we tested microporous (<2 nm) carbon and mesoporous (2-50 nm) carbon as host materials for the Li metal anode to avoid their degradation during cycling of lithium metal batteries (LMBs). Mesoporous carbon was more effective than microporous carbon as a host material to confine the Li metal and the lifetime of mesoporous carbon was more than twice as long as those of the Cu foil and microporous carbon. After confirmed better anode performance of mesoporous carbon host material, we applied Li-plated mesoporous carbon as an anode in a lithium-sulfur battery (Li-S) full cell. This research work suggests that mesopores, in spite of their low specific surface area, are better than micropores in stabilizing the Li metal and that a mesoporous host material can be applied to Li metal anodes for use in next-generation battery applications.11Nsciescopu
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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