Preparation of MgO catalytic support in shaped mesoporous high surface area form

Shaped MgO support of high surface area (307-397 m(2) g(-1)), mesoporous texture and good hardness was prepared by hydration/ calcination of commercial, low surface area MgO. For MgO(w), the paste MgO/H2O was kneaded, extruded, dried at room temperature and calcined in a fixed bed reactor at high space velocity of air flow. The samples MgO(m) and MgO(et) were prepared by the new simplified sol-gel method: MgO(w) was treated with methanol/water and ethanol/water mixture, respectively, and calcined. Texture of our MgO was evaluated by N-2 adsorption and compared with our data for commercial Al2O3 supports and literature data for MgO prepared by the original sol-gel method. Al2O3 exhibited a narrow distribution of pore diameters (dp) with the maximum at 6-11 nm and the small amount of pores with d, above 20 nm. Our MgO(w) exhibited a broader distribution with an important amount of pores with d, above 20 nm. Our MgO(m) and MgO(et) exhibited a broader N-2, adsorption hysteresis loop than MgO(w); their pores distribution became similar to that of Al2O3. N2 adsorption isotherms for the original sol-get MgO (350400 m(2) g(-1)) published in literature show different features as compared with our MgO and Al2O3. Our MgO exhibited a similar XRD peaks broadening as described in literature for the original sol-gel MgO, but somewhat different ratio of the heights of XRD peaks. The weight of our MgO, increased by about 40% at ambient air, indicating deep hydration of the sample. (C) 2004 Elsevier Inc. All rights reserved.