The Effect of Mg and Zn Dopants on Pt/Al2O3 for the Dehydrogenation of Perhydrodibenzyltoluene
| Autor: | Phillimon Modisha, Jacobus Visagie, Pieter van Helden, Rudaviro Garidzirai, Innocent Shuro, Dmitri Bessarabov |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Materials science
Hydrogen Scanning electron microscope chemistry.chemical_element 02 engineering and technology dopants lcsh:Chemical technology 010402 general chemistry 01 natural sciences Catalysis lcsh:Chemistry Ammonia chemistry.chemical_compound liquid organic hydrogen carriers Desorption lcsh:TP1-1185 Dehydrogenation Physical and Theoretical Chemistry by-products Chloroplatinic acid 021001 nanoscience & nanotechnology 0104 chemical sciences lcsh:QD1-999 chemistry dehydrogenation Chemisorption dibenzyltoluene 0210 nano-technology Nuclear chemistry |
| Zdroj: | Catalysts, Vol 11, Iss 490, p 490 (2021) Catalysts Volume 11 Issue 4 |
| ISSN: | 2073-4344 |
| Popis: | The effects of Mg and Zn dopants on the catalytic performance of Pt/Al2O3 catalyst were investigated for dehydrogenation of perhydrodibenzyltoluene (H18-DBT) as a liquid organic hydrogen carrier. Al2O3 supports were modified with Mg and Zn to produce Mg-Al2O3 and Zn-Al2O3 with a target loading of 3.8 wt.% for dopants. The modified supports were impregnated with chloroplatinic acid solution to produce the catalysts Pt/Al2O3, Pt/Mg-Al2O3 and Pt/Zn-Al2O3 of 0.5 wt.% Pt loading. Thereafter, the catalysts were characterised using inductively coupled plasma- optical emission spectrometry, scanning electron microscopy-energy dispersive X-ray spectroscopy, hydrogen temperature-programmed reduction, carbon-monoxide pulse chemisorption, ammonia temperature-programmed desorption, X-ray diffraction and transmission electron microscopy. The dehydrogenation experiments were performed using a horizontal plug flow reactor system and the catalyst time-on-stream was 22 h. Pt/Mg-Al2O3 showed the highest average hydrogen flowrate of 29 nL/h, while an average of 27 nL/h was obtained for both Pt/Al2O3 and Pt/Zn-Al2O3. This has resulted in a hydrogen yield of 80% for Pt/Mg-Al2O3, 71% for Pt/Zn-Al2O3 and 73% for Pt/Al2O3. In addition, the conversion of H18-DBT ranges from 99% to 92%, Pt 97–90% and 96–90% for Pt/Mg-Al2O3, Pt/Zn-Al2O3 and Pt/Al2O3, respectively. Following the latter catalyst order, the selectivity to dibenzyltoluene (H0-DBT) ranges from 78% to 57%, 75–51% and 71–45%. Therefore, Pt/Mg-Al2O3 showed improved catalytic performance towards dehydrogenation of H18-DBT. |
| Databáze: | OpenAIRE |
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