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Dimethyl Ether Hydrolysis over $WO_{3}/γ-Al_{2}O_{3}$ Supported Catalysts
| Content Provider | MDPI |
|---|---|
| Author | Smyrnioti, Maria Ioannides, Theophilos |
| Copyright Year | 2022 |
| Description | Dimethyl ether (DME) is considered an alternative hydrogen carrier with potential use in fuel cells and automotive and domestic applications. Dimethyl ether hydrolysis to methanol is a thermodynamically limited reaction catalyzed by solid-acid catalysts, mainly $Al_{2}O_{3}$ and zeolites. Moreover, it is the rate-limiting step of the DME steam reforming reaction, which is employed for the production of hydrogen fuel for fuel cell feeding. In the present study, the performance of $WO_{3}/Al_{2}O_{3}$ catalysts (0–44% wt. $WO_{3}$) was tested in DME hydrolysis reaction. The catalysts were characterized by means of $N_{2}$-physisorption, XRD, Raman spectroscopy, XPS, $NH_{3}$-TPD and 2,6-di-tert-butylpyridine adsorption experiments. The reaction rate of DME hydrolysis exhibited a volcanic trend as a function of tungsten surface density, while the best-performing catalyst was $37WO_{3}/Al_{2}O_{3}$, with a tungsten surface density of 7.4 $W/nm^{2}$, noting that the theoretical monolayer coverage for the specific system is 4–5 $W/nm^{2}$. Brønsted acidity was directly associated with the catalytic activity, following the same volcanic trend as a function of tungsten surface density. Blocking of Brønsted acid sites with 2,6-di-tert-butylpyridine led to a dramatic decrease in hydrolysis rates by 40 times, proving that Brønsted acid sites are primarily responsible for the catalytic activity. Thus, the type and strength rather than the concentration of acid sites are the key factors influencing the catalytic activity. |
| Starting Page | 396 |
| e-ISSN | 20734344 |
| DOI | 10.3390/catal12040396 |
| Journal | Catalysts |
| Issue Number | 4 |
| Volume Number | 12 |
| Language | English |
| Publisher | MDPI |
| Publisher Date | 2022-04-01 |
| Access Restriction | Open |
| Subject Keyword | Catalysts Applied Chemistry Dimethyl Ether Hydrolysis Tungsten Oxide Alumina Wo3/al2o3 |
| Content Type | Text |
| Resource Type | Article |
