Effect of phase composition between nano γ- and χ-Al2O3 on Pt/Al2O3 catalyst in CO oxidation

Synthesis of -Al2O3 Catalyst Support from Kaolin of Indonesian Origin

“…The list of diffraction peaks of the product in Figure 3 is presented in Table 5. With the exception of the peak at 26.7 o , the peaks observed for the final product are quite consistent with those of the pure -Al 2 O 3 phase described by Meephoka, et al [20], which exhibits diffraction peaks at 2 angles of 32, 37, 39, 45, 61, and 66 o . Yang, et al [12] also observed a rather weak peak in the vicinity of 2 = 27 o in their boehmite phase.…”

Catalytic Ethanol Dehydration to Ethylene over Nanocrystalline χ- and γ-Al₂O₃ Catalysts

“…Nanocrystalline alumina having different chi and gamma phases Table 1 were prepared by the solvothermal method according to the procedure described by Meephoka et al 21 . 25 g of aluminium isopropoxide AIP, 25g was dissolved in 100 ml with different ratios of mixed solvent butanol and toluene as shown in Table 1 in a test tube.…”

“…Certainly, the higher intensity of peak area at 43 can be attributed to the increase of χ-phase present in the catalysts. In addition, the γ-and χ-phase compositions of alumina catalysts were determined by the area of characteristic peak at 43 from the calibration curve obtaining from the XRD patterns of the physical mixture between single γ-and χ-phase with different contents according to Meephoka et al 21 The effect of phase composition on the pore size and pore size distribution of catalysts measured by the nitrogen adsorption-desorption is shown in Figs. 2a and 2b.…”

“…The previous studies show that highly stable nanocrystalline Al 2 O 3 with mixed γ-and χ-crystalline phases prepared by the solvothermal method resulted in interesting outcomes. It can be employed as catalyst supports in many catalytic reactions such as CO oxidation 21 , and propane oxidation 22 .…”

A Comparative Study of Different Al-based Solid Acid Catalysts for Catalytic Dehydration of Ethanol

“…There are many methods to synthesize alumina catalysts such as solvothermal synthesis, sol-gel synthesis, flame spray pyrolysis, precipitation, emulsion evaporation, microwave synthesis, hydrothermal synthesis and heat treatment of aluminium hydroxides such as boehmite and gibbsite. The solvothermal and sol-gel methods are commonly used for synthesis of alumina [14]. The γ-Al2O3 and mixed γ-χ phase Al2O3 catalysts were also investigated for this reaction because they exhibit high thermal stability, fine particle size, high surface area, inhibit side reaction and high acidity, which is enough to produce ethylene via ethanol dehydration.…”