硅胶包覆型催化剂在气相法合成碳酸二甲酯中的性能

Preparation of Silica-Coated Catalyst for Gas-Phase Oxidative Carbonylation to Dimethyl Carbonate

针对甲醇气相氧化羰基化直接合成碳酸二甲酯反应,采用溶胶凝胶法制备了硅胶包覆的新型多相催化剂PdCl_2-CuCl_2-KOAc-AC@SiO_2。考察了硅胶/活性炭/金属活性组分量的比对催化剂性能的影响。结果表明,硅溶胶/活性炭/金属活性组分的量比(mL/g/g)为22.0:4.5:1.0时,碳酸二甲酯的空时收率(STY)较负载型PdCl_2-CuCl_2-KOAc/AC催化剂提高了21%。并且包覆型催化剂在空气中的存放稳定性明显优于负载型催化剂,易于保存。催化剂活性的提高是SiO_2和AC载体协同作用的结果,SiO_2提高了催化剂的存放稳定性。

The novel silica-coated catalyst （PdClz-CuCl2-KOAc-AC@SiO2） via sol-gel method was developed for dimethyl carbonate （DMC） synthesis by gas-phase oxidative carbonylation of methanol. Effect of the ratio of silica-gel, AC and Pd-Cu-K on the performance of PdClz-CuCl2-KOAc-AC@SiO2 catalyst for DMC synthesis were investigated. The results showed that the reaction activity of PdCl2- CuCl2-KOAc-AC@SiO2 catalyst was the highest when the ratio of silica-gel, AC and Pd-Cu-K was 22.0 ： 4.5 ： 1.0（mL/g/g）, that the space-time yield （STY） of DMC was 9.1% higher than that of the supported solid PdCl2-CuCl2-KOAc/AC catalyst, and its storage stability in the air was superior to that of later. The improvement of catalyst activity should be attributed to the synergy of SiO2 and AC, and storage stability was improved due to SiO2.