Platinum

About: Platinum is a research topic. Over the lifetime, 49675 publications have been published within this topic receiving 1150035 citations. The topic is also known as: Pt & element 78.

Reversing the charge transfer between platinum and sulfur-doped carbon support for electrocatalytic hydrogen evolution

Abstract: Metal–support interaction is of great significance for catalysis as it can induce charge transfer between metal and support, tame electronic structure of supported metals, impact adsorption energy of reaction intermediates, and eventually change the catalytic performance. Here, we report the metal size-dependent charge transfer reversal, that is, electrons transfer from platinum single atoms to sulfur-doped carbons and the carbon supports conversely donate electrons to Pt when their size is expanded to ~1.5 nm cluster. The electron-enriched Pt nanoclusters are far more active than electron-deficient Pt single atoms for catalyzing hydrogen evolution reaction, exhibiting only 11 mV overpotential at 10 mA cm−2 and a high mass activity of 26.1 A mg−1 at 20 mV, which is 38 times greater than that of commercial Pt/C. Our work manifests that the manipulation of metal size-dependent charge transfer between metal and support opens new avenues for developing high-active catalysts. The charge transfer between metal and support is significant for catalysis, but little attention has been focused on charge transfer tuned by metal size. Here, authors report a metal size-dependent reversal of charge transfer between metal and carbon support in hydrogen evolution electrocatalysts.

Purification of platinum and gold structures after electron-beam-induced deposition

Abstract: The technique of electron-beam-induced deposition (EBID), when performed with organic precursors, typically results in relatively low metal content due to the partial decomposition of the organic precursor, leaving carbon-rich remnants in the deposition Here we describe a method applied to noble-metal structures deposited using EBID, consisting of a post-treatment step of heating in a reactive atmosphere of oxygen, whereby the amount of carbon in the structure is strongly reduced As a result, we have been able to increase the purity of platinum deposits from 15 at% to nearly 70 at%, and gold similarly from 8 at% to nearly 60 at% The resistivity of these structures has also been improved by up to four orders of magnitude, to achieve (14 ± 02) × 104 µΩ cm in the case of platinum

Catalytic Decomposition of Nitric Oxide on Zirconia by Electrolytic Removal of Oxygen

Abstract: Zirconia stabilized with 8 mole per cent of scandia has a very high oxygen ion conductivity and can "pump" oxygen from oxygen‐bearing gases thus decomposing them In this study the rate of decomposition of the air‐pollutant species, nitric oxide, to harmless species (via the reaction: ) was found to be markedly catalyzed when a potential above 1V was applied across a zirconia disk coated with either a porous platinum or porous gold electrode It is known that platinum can both form oxides and catalyze the decomposition of ; whereas, gold does neither The catalytic decomposition of on platinum metal is inhibited by , such behavior being attributed to preferential chemisorption of over as well as the possible formation of an inhibiting platinum oxide surface The original rationale for this investigation was the possibility that the decomposition of might be enhanced if were electrolytically "pumped" away from a platinum electrode deposited on zirconia, keeping the platinum oxygen‐free However it was not anticipated that at high potentials dissociation rates a thousandfold that on nonporous platinum electrodes occur in the presence of either a platinum or gold porous electrode No reactivity at all was observed on a nonporous gold electrode These results suggest that catalysis occurs mainly on a surface other than the platinum or gold, namely, on the zirconia surface itself It is proposed that F‐centers on the zirconia surface formed by the applied potential are primarily responsible for the observed enhanced catalysis