Methanol oxidation on pure and platinum-doped tungsten oxide supported by activated carbon

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F19%3A10405820" target="_blank" >RIV/00216208:11320/19:10405820 - isvavai.cz</a>

Výsledek na webu

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=Y8Nh0Ztt1V" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=Y8Nh0Ztt1V</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.matchemphys.2019.02.042" target="_blank" >10.1016/j.matchemphys.2019.02.042</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Methanol oxidation on pure and platinum-doped tungsten oxide supported by activated carbon

Popis výsledku v původním jazyce

Thin films of pristine and platinum-doped tungsten oxide were examined as potential catalysts for efficient partial oxidation of methanol. The tungsten oxide layers with different thicknesses were deposited by the means of reactive magnetron sputtering on oxidized silicon wafer and silicon coated with carbon activated via ion etching. Morphology and chemical analysis were checked before and after the reaction by X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). It was found that while pure tungsten oxide layers on silicon exhibit relatively small hydrogen production rates and high ratio of carbon oxides, both etched carbon interlayer (as long as the oxide thickness is low enough) and platinum doping can lead to significant improvement of reactivity, increasing hydrogen yield and decreasing fraction of undesired carbon monoxide in the product mix. It is suggested that it is due to the strong electronic interaction between WOx and Pt or active C, increasing the acidity of the tungsten oxide reaction sites and thus altering its reactivity preference from methanol dehydration towards dehydrogenation. If both species are present in a very thin oxide, however, the competing electronic interactions lead to partial reduction of their positive effect. As prepared sputtered thin films are chemically and morphologically unstable under reducing environment of methanol oxidation reaction, but the presence of dispersed Pt in the layer substantially stabilizes its physical structure.

Název v anglickém jazyce

Methanol oxidation on pure and platinum-doped tungsten oxide supported by activated carbon

Popis výsledku anglicky

Thin films of pristine and platinum-doped tungsten oxide were examined as potential catalysts for efficient partial oxidation of methanol. The tungsten oxide layers with different thicknesses were deposited by the means of reactive magnetron sputtering on oxidized silicon wafer and silicon coated with carbon activated via ion etching. Morphology and chemical analysis were checked before and after the reaction by X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). It was found that while pure tungsten oxide layers on silicon exhibit relatively small hydrogen production rates and high ratio of carbon oxides, both etched carbon interlayer (as long as the oxide thickness is low enough) and platinum doping can lead to significant improvement of reactivity, increasing hydrogen yield and decreasing fraction of undesired carbon monoxide in the product mix. It is suggested that it is due to the strong electronic interaction between WOx and Pt or active C, increasing the acidity of the tungsten oxide reaction sites and thus altering its reactivity preference from methanol dehydration towards dehydrogenation. If both species are present in a very thin oxide, however, the competing electronic interactions lead to partial reduction of their positive effect. As prepared sputtered thin films are chemically and morphologically unstable under reducing environment of methanol oxidation reaction, but the presence of dispersed Pt in the layer substantially stabilizes its physical structure.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10305 - Fluids and plasma physics (including surface physics)

Projekt

—

Návaznosti

S - Specificky vyzkum na vysokych skolach<br>I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2019

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Materials Chemistry and Physics

ISSN

0254-0584

e-ISSN

—

Svazek periodika

228

Číslo periodika v rámci svazku

Apr

Stát vydavatele periodika

CH - Švýcarská konfederace

Počet stran výsledku

13

Strana od-do

147-159

Kód UT WoS článku

000468252700020

EID výsledku v databázi Scopus

2-s2.0-85061858834