| Autor: |
Tamura, Kazuya, Kokuryo, Shinya, Kitamura, Haruna, Hernandez Gaitan, Jose Andres, Tsubota, Soshi, Miyake, Koji, Uchida, Yoshiaki, Nishiyama, Norikazu |
| Zdroj: |
Industrial & Engineering Chemistry Research; 20240101, Issue: Preprints |
| Abstrakt: |
Catalyst deactivation owing to carbon deposition on Ni-based catalysts is a serious problem in reactions involving hydrocarbon compounds. In particular, the catalytic decomposition of methane (CDM), which produces hydrogen and carbon, cannot prevent carbon deposition on the catalysts. Because the formation of carbon-coated Ni particles leads to a decrease in activity, it is necessary to generate carbon nanotubes tipped with Ni particles. Herein, this work reports Cr and Ni catalysts supported by dealuminated beta zeolites. Cr and Ni loaded on dealuminated beta zeolites showed remarkably higher CDM activity and longer catalyst lifetime than only Ni loaded on dealuminated beta zeolites. The optimal loading amounts of Ni and Cr were 50 and 1 wt %, respectively. The maximum H2yield over the optimal Cr and Ni loaded on dealuminated beta zeolite was 22.5%, while that over only Ni (50 wt %) loaded on dealuminated beta zeolite was 16.5%. The state of the metal species was investigated using hydrogen temperature-programmed reduction measurements and determined the optimum reduction conditions. In addition, the deposited carbon was evaluated by using thermogravimetric analysis, transmission electron microscopy, and Raman spectroscopy. Cr3+species enhance catalytic activity and contribute to the formation of highly crystalline carbon nanotubes. |
| Databáze: |
Supplemental Index |
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