碳化硅协同分子筛负载型催化剂微波辅助催化氧化甲苯性能

Synergetic Effects of Silicon Carbide and Molecular Sieve Loaded Catalyst on Microwave Assisted Catalytic Oxidation of Toluene

实验采用浸渍法制备分子筛负载型催化剂,微波场中利用吸波材料碳化硅和催化剂催化氧化甲苯废气.考察了碳化硅与分子筛负载铜-钒催化剂混合比及混合方式等条件变化对甲苯降解的影响,并通过电镜扫描、比表面积测试和X射线衍射分析等手段对催化剂进行了表征.研究表明,在固定床反应器底部装填质量比20%的碳化硅时,反应器兼有蓄热性能和低温催化氧化的优点,可有效提高微波能的利用和甲苯的催化氧化效率;微波功率75 W和47 W作用下,分子筛负载铜-钒催化剂和负载铜-钒-铈催化剂对甲苯的完全燃烧温度分别为325℃和160℃.表征发现,稀土元素铈的掺杂提高了活性组分在催化剂表面的分散度,催化剂的微孔结构保证了其对甲苯的高吸附性能,而非晶相型铜、钒氧化物的存在则提高了催化剂的催化活性.

Molecular sieve loaded catalyst was prepared by impregnation method,microwave-absorbing material silicon carbide and the catalyst were investigated for catalytic oxidation of toluene by microwave irradiation.Research work examined effects of silicon carbide and molecular sieve loading Cu-V catalyst＇s mixture ratio as well as mixed approach changes on degradation of toluene,and characteristics of catalyst were measured through scanning electron microscope,specific surface area test and X-ray diffraction analysis.The result showed that the fixed bed reactor had advantages of both thermal storage property and low-temperature catalytic oxidation when 20% silicon carbide was filled at the bottom of the reactor,and this could effectively improve the utilization of microwave energy as well as catalytic oxidation efficiency of toluene.Under microwave power of 75 W and 47 W,complete-combustion temperatures of molecular sieve loaded Cu-V catalyst and Cu-V-Ce catalyst to toluene were 325℃ and 160℃,respectively.Characteristics of the catalysts showed that mixture of rare-earth element Ce increased the dispersion of active components in the surface of catalyst,micropore structure of catalyst effectively guaranteed high adsorption capacity for toluene,while amorphous phase of Cu and V oxides increased the activity of catalyst greatly.