Preparation of Nanometer Magnesia with High Surface Area and Study on the Influencing Factors of the Preparation Process

Abstract Three kinds of MgC 2 O 4 ·2H 2 O were prepared by the precipitation method with different raw materials, and MgO with high surface area was obtained via thermal decomposition of MgC 2 O 4 ·2H 2 O in different atmospheres. The precursor MgC 2 O 4 ·2H 2 O and as-prepared MgO were characterized by XRD, BET, TEM, and TG-DTA measurements. It was found that using Mg(CH 3 COO) 2 ·4H 2 O and H 2 C 2 O 4 ·2H 2 O as the starting materials and calcining the precursor MgC 2 O 4 ·2H 2 O in flowing dry gas are the key factors to obtain high surface area for MgO. The MgO prepared at the optimum condition is composed of nanocrystals with a size of about 4–5 nm and forms a wormhole-like porous structure with a specific surface area of 534 m 2 ·g −1 after calcining at 520 °C. In addition, the MgO has good thermal stability; after being calcined at 650 °C and 800 °C for 2 h, its surface area is still 229 m 2 ·g −1 and 134 m 2 ·g −1 , respectively.