【摘要】 在全球化石能源面临枯竭的背景下，提高石油资源的利用率是应对能源供给压力、实现资源价值最大化的关键路径。稀土改性分子筛在催化裂化重质原油转化为高价值产品中已展现出良好的应用前景，然而稀土元素的形态和分布对分子筛催化性能的影响仍有待充分阐明。基于此，对稀土元素Ce改性Beta分子筛催化剂进行了催化裂化性能的研究，相比于不含Ce物种的P-Beta和仅含CeO₂物种的CeO₂-Beta,Ce-Beta表现出最优的正十六烷催化裂化性能，在280℃、1 h内，能够实现88.6%的正十六烷转化率和82.5%的液态产物收率，其中，液态产物主要是由以C₈为中心的短链烃和极少量的偶联产物（～5%）组成。此外，通过多种构-效实验表明Ce物种是以Beta分子筛微孔内部的Ce离子和分子筛表面的外部CeO₂簇的形式共存的，二者协同作用增加了酸浓度的同时，增强了对底物分子和烯烃中间体的吸附能力，从而显著提高了Ce-Beta的催化裂化活性。更多还原

【Abstract】 The catalytic cracking of heavy crude oil into high-value products over rare earth（RE）-modified zeolite is a potential strategy for improving the utilization efficiency of non-renewable petroleum resources. However, the influence of the speciation and distribution of rare earth elements on the catalytic properties of zeolites remains to be fully elucidated. In this work, we synthesized a highly efficient rare earth element Ce-modified Beta zeolite catalyst（Ce-Beta） for the catalytic cracking of n-hexadecane, which exhibits 88. 6% n-hexadecane conversion with 82. 5% yield of liquid products. Through multiple experimental studies, we revealed that the Ce species coexist in the form of internal Ce ions inside the zeolite micropores and external CeO₂ clusters on the zeolite surface, both of which synergistically increase the acid concentration and strengthen the adsorption capacity for substrates and olefin intermediates, thus significantly enhancing the catalytic cracking activity of Ce-Beta.更多还原