Tunable activity of [Ga]HZSM-5 with H2 treatment: Ethane dehydrogenation

Catalytic performance of gallium oxide based-catalysts for the propane dehydrogenation reaction: effects of support and loading amount

“…As shown in Table 4, the ratio of well-dispersed Ga in 5Ga 2 O 3 /ZSM-5 to 5Ga 2 O 3 /Al 2 O 3 is approximately equal to that of the strong acid peak area in the corresponding samples. This similar phenomenon was also mentioned by Ausavasukhi et al 25 In addition, a small peak at about 690 C can be noticed, which should be attributed to the reduction of OH groups or Al of alumina support. 41 On the other hand, Fig.…”

“…In general, for Ga 2 O 3 -supported catalysts, there are three kinds of active centers in the fresh catalysts: welldispersed Ga species, GaO + and bulk Ga 2 O 3 . 25,47 The welldispersed Ga species and GaO + usually have higher dehydrogenation activity as compared with bulk Ga 2 O 3 . 25 It can be seen from the H 2 -TPR curves in Fig.…”

“…16,[22][23][24] The various gallium species (Ga 2 O 3 , GaO + and Ga + ) as active constituents exhibited different performances for light alkane dehydrogenation reaction. 25 In addition, Nowak et al 26 also reported the dispersion of Ga 2 O 3 species varied with different supports. However, the effects of supports on the state of gallium species have not been fully understood, especially the causes of these changes.…”

Aromatization over nanosized Ga-containing ZSM-5 zeolites prepared by different methods: Effect of acidity of active Ga species on the catalytic performance

“…The coked catalyst was heated at a heating rate of 10 °C/min under an air atmosphere. 13 C CP-MAS NMR spectroscopy was performed using a double resonance probe CPMAS with 7 mm rotors with a standard pulse sequence. The 1-hexene TPD-MS was conducted on an AutoChem II 2920 Chemisorption Analyzer apparatus equipped with the OmniStar 300 Mass Spectrometer to record the evolved H 2 signal.…”

“…In previous studies, a simple impregnation method for Gaincorporation was adopted, and the nature of the active gallium species was investigated. Ausavaukhi et al [13] prepared a series of Ga-containing ZSM-5 zeolites via impregnation and physical mixing and determined that the GaO + species act as stronger Lewis acid sites. Xiao et al [14,15] also reported that the extraframework GaO + species in impregnated ZSM-5 samples can react with the acidic protons of the zeolite framework and contribute to a strong Lewis acidity, which is favorable for dehydrogenation during propane aromatization under a N 2 atmosphere.…”