The fluidized bed catalysts of Cr-K/γ-Al2 O3 were prepared by microwave method and characterized. Also the cata-lytic activities for isobutane dehydrogenation were evaluated, through which the relationship between the structure and per-formance of the catalysts, as well as the mechanism of microwave effect were analyzed. It was found that the particle size of active constituent on catalyst surface is decreased by microwave method, and the dispersion of active constituent on the sup-porter is improved in contrast to the catalyst prepared by conventional method. The part active Cr6+species occupies sites on/in A12 O3 in close vicinity of tetrahedral 27 Al in the catalyst prepared by microwave, forming the stable structure of-Al-O-Cr-O-Al-. Also in the catalyst prepared by microwave isolated Cr6+, mono and polychromate species are more than those pre-pared by conventional method, which play a key role in the isobutane dehydrogenation. The microwave method can reduce the preparation time of catalyst, increase the activity, high thermal stability, as well as good abrasion resistance, which ex-tends the catalyst life.%采用微波技术制备并表征Cr-K/γ-Al2 O3流化床催化剂，评价其催化异丁烷脱氢制异丁烯的性能，分析催化剂结构与催化性能的关系和微波作用机制。结果表明：与传统法制备的催化剂相比，微波制备法降低了催化剂中活性组分的晶粒度，活性组分的分散度增加；微波法制备的催化剂部分活性Cr6+物种占据了氧化铝载体表面及内部四配位体附近的空穴，可形成稳定的—Al—O—Cr—O—Al—结构；微波法制备的催化剂中，单个Cr6+物种及低聚体的Cr6+物种多于传统制备的催化剂，而这两种活性铬物种在异丁烷催化脱氢反应中起着非常重要的作用；采用微波技术可缩短催化剂制备时间，提高其活性、稳定性和耐磨性，延长催化剂寿命。
展开▼
