A series of HZSM-5 zeolites modified by different amounts of phosphorus were prepared, and their performances for the catalytic cracking of the mixed C4 alkanes to produce light olefins were investigated. The results showed that the introduction of phosphorus into HZSM-5 zeolite greatly enhanced the selectivity to light olefins, especially to propylene. XRD and acidity characterization on P/HZSM-5 catalysts showed that the framework structure of HZSM-5 was scarcely damaged after P modification, and the introduction of P modulated the amount of acidic sites and the percentage of weak acidic sites in total acidic sites. CO2-TPD analysis showed that new basic sites were generated on the surfaces of P/HZSM-5 catalysts, and thus inhibited the adsorption of intermediate olefins and lowered the formation of aromatics. The fact that phosphorus addition could modify both the acidic and basic characteristics of HZSM-5 zeolites which in turn promoted its catalytic performance, will throw new light on the design of novel catalysts for the production of light olefins.
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机译：制备了一系列由不同量的磷改性的HZSM-5沸石，研究了混合C4烷烃的催化裂化以产生光烯烃的性能。结果表明，将磷引入HzSM-5沸石大大提高了对光烯烃的选择性，尤其是丙烯。 P / HZSM-5催化剂上的XRD和酸度表征显示，P改性后HZSM-5的骨架结构几乎损坏，P的引入调节酸性位点的量和总酸性位点的弱酸位点的百分比。 CO2-TPD分析表明，在P / HZSM-5催化剂的表面上产生了新的碱性位点，因此抑制中间烯烃的吸附并降低了芳烃的形成。磷添加可以改变HZSM-5沸石的酸性和基本特征，这反过来促进其催化性能，将对新型催化剂的设计进行新的催化剂，用于生产光烯烃。
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