1. Used as an active component of the catalyst
Hebei Messi Biology Co., Ltd. stated that magnesium oxide has a strong alkalinity and is used alone as a solid base catalyst (such as MgO, MgO/NaY and MgO/ZrO2) or as a compound acid-base bifunctional catalyst (such as MgO/HMCM-22 and MgO-Al2O3) to catalyze reactions such as transesterification, Knoevenagel condensation and Claisen-Schmidt condensation. The activity of the catalyst depends on the preparation method and reaction conditions. The effect of the preparation method on the surface morphology and properties of magnesium oxide was studied, and the Meerwein-Ponndorf-Verlev reduction reaction was selected as the model reaction. It was found that the direct calcination method has a wide range of reaction raw materials and the catalytic activity of the obtained magnesium oxide is high. The magnesium oxide after the reaction is activated and reused, and the specific surface area and catalytic activity remain unchanged.
2. Used as a catalyst carrier
There are usually two methods for preparing magnesium oxide supported catalysts: one is to prepare MgO first, select a suitable method to optimize the specific surface area and pore size distribution of MgO, and then deposit the active components on MgO, and improve the deposition technology of the active components (heterogeneous impregnation or thermal diffusion) to avoid damaging the carrier. The other is to deposit active metals, metal oxides or their precursors simultaneously when preparing MgO, such as calcining Co(Ni) and MoO3 or their precursors with Mg(OH)2.
3. Used as a catalyst promoter
As an additive, magnesium oxide can improve the activity and stability of the catalyst, improve the catalyst structure and pH, and is used for reactions such as synthesis gas conversion, hydrogenation and dehydrogenation. The amount of MgO doping affects the structure and performance of the catalyst. Preparation of magnesium oxide doped bifunctional catalyst Cu-Zn-Mg/y-Al2O3 catalyzes synthesis gas to produce dimethyl ether. The catalytic performance is best when the magnesium oxide content is 20mol% (CO conversion rate 37%, dimethyl ether selectivity 83%, by-product selectivity 14%). The catalyst components are evenly dispersed, the acidity is appropriate, the pore size is small, and it has a malachite-type crystal structure. When the MgO content increases to 30 mol%, the catalyst crystal structure disappears, resulting in a decrease in catalytic activity.