189,862 research outputs found
Nano-catalizzatori polimetallici per elettro-ossidazione di metanolo e relativo metodo di preparazione
No full textSYNTHESIS AND CHARACTERIZATION OF PLATINUM RUTHENIUM BIMETALLIC NANOPARTICLES AS CATALYSTS FOR DIRECT METHANOL FUEL CELLS
No full textNovel Pt-Ru nanoparticles formed by vapour deposition as efficient electrocatalyst for methanol oxidation, Part II. Electrocatalytic activity
No full textThe methods developed and described in paper–part I are employed to prepare nanometer size Pt-Ru particles on a Vulcan XC72R substrate with controlled metal loading. Transmission Electron Microscopy (TEM) confirmed uniform particles size (average diameter 2nm) and homogeneous dispersion of the particles over the substrate. Energy Dispersive X-ray absorption (EDX) analysis confirmed the compositional homogeneity. The catalytic activity of these supported nanoparticles with regard to methanol electrooxidation is investigated using cyclic voltammetry (CV), chronoamperometry (CA) and CO-stripping voltammetry techniques at temperatures between 25°C and 60°C. Such investigation concerns supported catalysts prepared with c.a. 10 and 18 wt% overall metal loading (Pt + Ru) onto the Vulcan XC72R substrate. Comparative testing of our catalysts and a commercial Pt-Ru/Vulcan reveals markedly superior activity for our catalysts. In fact, we observe for the latter a five-fold increase of the oxidation current as compared to a commercial Pt-Ru/Vulcan with equal metal loading. One of the reasons for the greater activity is found to be the very high dispersion of the metals over the substrate, i.e. the large surface area of the active phase. Other reasons are plausibly ascribable to the varied Pt/Ru composition and/or reduced presence of contaminants at the catalyst surface
Pt-Ru-Ir Nanoparticles Prepared by Vapor Deposition as a Very Efficient Anode Catalyst for Methanol Fuel Cells
No full textPreparation of Pt-Ru-Ir nanoparticle catalysts on carbon black by a novel vapour deposition method is reported. Particle size as assessed by TEM is c.a. 2.5 nm with narrow distribution. Moreover, they are homogeneously dispersed on the substrate. The electrocatalytic activity of the particles towards methanol electrooxidation was investigated by cyclic voltammetry, chronoamperometry at constant potential and adsorbed CO-stripping voltammetry. It was found that these catalysts possess outstanding activity for methanol electrooxidation. This is over one order of magnitude higher than in state of art catalysts. The novel catalysts have the potential to bear significant performance improvement of DMFCs
Novel ternary metal Pt-based nanoparticle catalysts prepared by vapour deposition with very strong activity towards methanol electrooxidation
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supplementary_data – Supplemental material for Buckling behaviour and design of complex-shaped aluminium mullion sections
No full textSupplemental material, supplementary_data for Buckling behaviour and design of complex-shaped aluminium mullion sections by Sivakumar Kesawan and Mahen Mahendran in Advances in Structural Engineering</p
Studies on Sono-Chemical Biodiesel Production Using Smoke Deposited Nano MgO Catalyst
No full textThe comprehensive study of smoke deposited nano sized MgO as a catalyst for biodiesel production was investigated. The transesterification reaction was studied under constant ultrasonic mixing for different parameters like catalyst quantity, methanol oil molar ratio, reaction temperature and reaction time. An excellent result of conversion was obtained at 1.5 wt% catalyst; 5:1 methanol oil molar ratio at 55°C, a conversion of 98.7% was achieved after 45 min. The conversion was three to five times higher than those are reported for laboratory MgO in literature. This was mainly due to the enhancement of surface area of the catalyst and the activity of ultrasonic waves. Catalyst is easily recovered and reused up to eight times with easy regeneration steps. © 2013 BCREC UNDIP. All rights reservedReceived: 18th March 2013; Revised: 20th August 2013; Accepted: 9th September 2013[How to Cite: Sivakumar, P., Sankaranarayanan, S., Renganathan, S., Sivakumar, P. (2013). Studies on Sono-Chemical Biodiesel Production Using Smoke Deposited Nano MgO Catalyst. Bulletin of Chemical Re-action Engineering & Catalysis, 8 (2): 89-96.(doi:10.9767/bcrec.8.2.4628.89-96)][Permalink/DOI: http://dx.doi.org/10.9767/bcrec.8.2.4628.89-96]</p
How could a natural catastrophe impact the ecology of a species? The Nicobar megapode and tsunami
No full textThis study on the impact of the 2004 tsunami on the Nicobar megapode Megapodius nicobariensis, endemic coastal living bird species in the Nicobar group of islands showed a significant decline (nearly 70%) in the number of individuals when compared to before tsunami populations (Paired sample test, t=2.061, df=14, p<0.05). The tsunami has also adversely influenced the nest-site selection of the megapodes. The post tsunami impact on this species is also expected to be severe, pushing the species into the category of "critically endangered"
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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