1. |
2. Synthesis of molybdenum carbide thin films for production of hydrogen via electrochemical water splitting : M. Sc. thesisCesur Altinkaya, 2018, magistrsko delo Ključne besede: molybdenum, platinum, molybdenum carbide thin films, hydrogen evolution reaction, water splitting, electrolysis, electrochemistry, pyrolysis, thin films
Objavljeno v RUNG: 30.08.2018; Ogledov: 4879; Prenosov: 0
Gradivo ima več datotek! Več... |
3. Atomically resolved dealloying of structurally ordered Pt nanoalloy as an oxygen reduction reaction electrocatalystAndraž Pavlišič, Primož Jovanovič, Vid Simon Šelih, Martin Šala, Marjan Bele, Goran Dražić, Iztok Arčon, Samo B. Hočevar, Anton Kokalj, Nejc Hodnik, Miran Gaberšček, izvirni znanstveni članek Opis: The positive effect of intermetallic ordering of platinum alloy nanoparticles on oxygen reduction reaction (ORR) activity has been well established. What is still missing is an understanding of selective leaching of the less noble metal from the ordered structure and its correlation to longterm ORR performance. Using a combination of kinetic Monte Carlo simulations and advanced characterization techniques, we provide unprecedented insight into dealloying of intermetallic PtCu3 nanoparticles a well-known binary alloy. Comparison of ordered and disordered samples with identical initial compositions and particle size distributions reveals an unexpected correlation: whereas the copper dealloying rates in the ordered and disordered counterparts are almost the same, in the ordered structure Pt atoms are surrounded by 15−30% more Cu atoms throughout all the stages of acid leaching. This more convenient Pt−Cu coordination explains the statistically significant increase of 23−37% in ORR activity of the ordered structure at all stages of alloy degradation.
Ključne besede: ORR activity, fuel cells, platinum alloy, nanoparticle stability, intermetallic ordering, kinetic Monte Carlo, dealloying, in situ ICP-MS
Objavljeno v RUNG: 27.09.2016; Ogledov: 5586; Prenosov: 0
Gradivo ima več datotek! Več... |
4. Novel applications of oxygenic photosynthetic organisms : dissertationDanijel Stojković, 2015, doktorska disertacija Opis: Inspired by natural microorganisms that possess a rigid cell wall to protect them in harsh conditions, individual cells of Chlamydomonas reinhardtii were artificially encapsulated with different materials and hydrogen production was enhanced.
The first attempt was to cover the cells with hydrated silicon dioxide, which is naturally formed by diatoms. The cells covered with silica were not able to produce hydrogen, but the improved TiO2-encapsualtion of Chlamydomonas reinhardtii was found to positively affect their hydrogen production under sulfur-deprived conditions. It was shown that incubation of the cells in the dark before exposure to light was necessary in order to overcome the toxic effects of the (RKK)4D8 catalytic peptide that is essential for TiO2 formation. The TiO2-encapsulated cells were able to produce H2 with about double efficiency during 5-day period compared to non-encapsulated cells. The light-to-H2 conversion efficiency of TiO2-encapsulated Chlamydomonas reinhardtii system was estimated to be more than 4 % under optimized conditions.
The encapsulation with platinum led us to discover the bioreductive properties of Chlamydomonas reinhardtii. Beside the homogeneous Pt reduction carried out by the algae, the most surprising discovery was the possibility to use algae culture for targeted heterogeneous nucleation. An important discovery was that is possible to control the nucleation mechanism and redirect predominantly homogeneous into fully heterogeneous nucleation.
Ključne besede: photosynthesis, H2 production, TiO2, encapsulation, Chlamydomonas reinhardtii, platinum reduction
Objavljeno v RUNG: 01.04.2015; Ogledov: 8277; Prenosov: 301
 Celotno besedilo (23,38 MB)
Gradivo ima več datotek! Več... |
