微波辅助催化氧化苯高性能催化剂实验研究

Preparation and application of high-performance catalyst in microwave assisted catalytic oxidation of benzene

采用传统浸渍法制备分子筛负载过渡金属和稀土元素催化剂,通过微波辅助催化氧化苯性能实验考察其催化活性。研究表明,天津科密欧的5A分子筛为优良的催化剂载体,分子筛负载铜-锰-铈催化剂对苯的完全燃烧温度为230℃,铜(Cu)锰(Mn)双金属催化剂中晶相与非晶相Cu1.5Mn1.5O4尖晶石提高了催化剂的催化活性,稀土铈(Ce)的助催化效果显著;30 h的连续性实验表明,Cu-Mn-Ce/分子筛催化剂具有良好的稳定性和高的催化活性。催化剂的比表面积和表面形貌表征表明,催化剂比表面积和孔径受高温煅烧和氧化反应而增大,从而有助于苯的吸附与氧化降解;X射线衍射表明,实验前后分子筛结构未发生明显变化,铜锰主要以二价和三价的氧化物形态分布于催化剂表面。

High-performance catalyst of molecular sieve supported transition metals and rare earth element was prepared by traditional impregnation method, and the catalytic activity was checked by microwave assisted catalytic oxidation of benzene in our study. It indicated that 5A type molecular sieve obtained from Tianjin kermel was an excellent carder, and molecular sieve supported copper （Cu）, manganese （Mn） and cerium （Ce） catalyst had a complete combustion temperature of 230 ℃ for benzene. The appearance of Cu1.5Mn1.5 O4 with crystalline spinel phase and amorphous phase improved the catalytic activity greatly, and the promoting effect of Ce was also significant. Molecular sieve loaded Cu-Mn-Ce catalyst showed good stability and high catalytic capacity after operating with 30 h. Based on the characteristics of the special surface area and surface morphology, it was found that the special surface area and pore size of the catalyst were enlarged during calcination and reaction, which are beneficial to the adsorption and oxidation of benzene. X-ray diffraction results showed that the crystalline structure of molecular sieve did not change significantly, and CuO and Mn2O3 were dispersed mainly onto the surface of the catalyst.