Ga2O3/HZSM-5 propane aromatization catalysts: Formation of active centers via solid-state reaction

An active and very selective catalyst for propane conversion to aromatics near atmospheric pressure and 750–850 K is formed by ball-milling 2–10 wt% Ga as Ga 2 O 3 with HZSM-5 followed by hydrogen reduction at about 850 K for 2 h. Microbalance TPR experiments and X-ray diffraction studies along with catalytic testing have helped establish that the intimate physical mixture of Ga 2 O 3 with HZSM-5, the acidity of the zeolite, and the hydrogen reduction are all necessary to generate the highly active form of the catalyst. The active species is probably Ga(I) as a zeolitic cation and is not incorporated in the zeolite lattice.