| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 39028 | Applied Catalysis A: General | 2016 | 7 Pages |
•Ru/γ-Al2O3 catalysts are modified with alkali hydroxides to enhance ammonia decomposition.•Analysis by solid state NMR and XRD measurements showed basic modification of the support by aluminate formation.•LiOH modification with very high loadings showed the best results (6.5 times higher activity compared to unmodified catalyst) because of a high concentration of basic sites and a partial preservation of the support porosity.
We herein present an easy approach to increase drastically the catalytic activity of Ru/γ-Al2O3 catalysts in ammonia decomposition by surface modification with alkali hydroxides. The best activities have been achieved by a catalyst modification with lithium hydroxide in a Li/Al ratio of 1.7. In contrast, coatings with potassium and caesium hydroxide caused mass transfer limitations in the catalytic material already at low amounts (ratios alkali/Al <0.2–0.3). MAS ssNMR and XRD studies indicate the in-situ formation of alkali aluminates resulting in a basic modification of the support.
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