Electrocatalytic Activity and Stability of Platinum Nanoparticles Supported on Carbon–Molybdenum Oxides for the Oxygen Reduction Reaction

Abstract

Leucosceptroids A and B are sesterterpenoids with potent antifeedant and antifungal activities. A more efficient gram‐scale total synthesis of leucosceptroid B and the first total synthesis of leucosceptroid A are presented. The key transformations include an aldol reaction between a substituted dihydrofuranone and an (S)‐citronellal‐derived aldehyde, a SmI2‐mediated intramolecular ketyl–olefin radical cyclization, and final‐stage alcohol oxidation.

Sacrificial Reducing Agent Free Photo-Generation of Platinum Nano Particle over Carbon/TiO2 for Highly Efficient Oxygen Reduction Reaction

“…Hence, researcher have been focusing on reducing the cost of the catalyst by reducing the amount of Pt used by adapting to a variety of carbon materials, use of transition metal oxides and doping of nitrogen in carbon. The year 2015, has seen more developments and attempts to improve the ORR activity by the addition of a metal oxide such as MoO x 3, TiO x 4 and CeO x 56, on the Pt/C catalyst. Incidentally some or most of these metal oxides fall in the category of photo-catalyst.…”

CO Tolerance and Stability of Proton Exchange Membrane Fuel Cells with Nafion® and Aquivion® Membranes and Mo‑Based Anode Electrocatalysts

“…Such observation has been also made from rotating disk electrode experiments in sulfuric acid solutions. 21 In this way, the Tafel plots clearly demonstrate that the single cell performance decays due to the anode cyclings observed in Figures 3 and 4 are not related to the single cell oxygen electrode.…”

“…The mixture was dried in a water bath at approximately 90 °C, with stirring. After complete evaporation of the solvent, the material was placed into a furnace at 70 °C for a period of 12 h. The material was then thoroughly macerated and pretreated at 100 °C under an argon atmosphere for 1 h, followed by heat treatment at 550 °C also under argon for 5 h. 21 Incorporation of Pt nanoparticles to form the Pt/MoO 2 -C electrocatalyst was made by reduction of a Pt precursor (H 2 PtCl 6 .6H 2 O; Alfa Aesar) with formic acid. [22][23][24] In brief, a portion of as-prepared MoO 2 -C support was weighed to give a final Pt/support ratio of 20 wt.% m/m and added to an aqueous solution of formic acid (0.5 M).…”

“…It is seen that the diffraction pattern for PtMo/C basically exhibit a peak of the carbon (2θ = 25°), and of the face centered cubic (fcc) crystalline structure of Pt at 2θ = 40°, 46°, 67°, 81°. For Pt/MoO 2 -C, the diffraction patterns predominantly exhibit the peaks of the fcc crystalline structure of Pt, but some small peaks evidence the presence of the crystalline phase of MoO 2 at 26°, 37°, 53°, 21 (see also the JCPDS-32-671 standard). The average crystallite sizes of Pt in these catalysts were calculated from the Pt (220) diffraction peak, using the Scherrer equation and the values (2.4-3.8 nm) obtained were included in Table 1.…”

Szén-monoxid-tűrő katalizátorok tüzelőanyag-elemekhez

“…A közelmúltban végzett vizsgálatok arra utalnak, hogy a Pt/C rendszer néhány problémája leküzdhető egy második, oxofil fém alkalmazásával. Általában a reaktív hidroxil csoportok könnyebben képződnek az oxofil adalékanyagon/dópoló anyagon, mint a platinán, ami nemcsak a hidrogén oxidációs reakció sebességet növeli [12][13][14], hanem a sokkal lassabb oxigén redukciós folyamatban is előnyös [15,16]. Továbbá megkönnyíti a CO, mint szennyezőanyag oxidációját az úgynevezett bifunkciós mechanizmuson keresztül [17,18] stabilitását, azaz a szinterelődés elkerülését a hőkezelés során [63].…”