Faculty of Chemistry, Jagiellonian University, 30-387 Kraków, Poland.
Faculty of Chemistry, Adam Mickiewicz University, 61-614 Poznan, Poland.
Molecules. 2020 Feb 19;25(4):926. doi: 10.3390/molecules25040926.
Zeolite-based catalysts are globally employed in many industrial processes, such as crude-oil refining and bulk chemical production. In this work, the cracking of low-density polyethylene (LDPE) was thoroughly followed in a FTIR operando study to examine the catalytic efficiency of purely microporous zeolites of various textural characteristics. To provide complementary and valuable information on the catalytic activity of the zeolite studied, the thermogravimetric analysis results were compared with yields of the products generated under operating conditions. The reaction products were analyzed via GC-MS to determine the hydrocarbon chain distribution in terms of paraffin, olefins, and aromatics. The individual impact of textural and acidic parameters on catalytic parameters was assessed. The accumulation of bridging hydroxyls of high strength in the zeolite benefited the decrease in polymer decomposition temperature. Through a strategic comparison of purely microporous zeolites, we showed that the catalytic cracking of LDPE is dominated by the acidic feature inherent to the microporous environment.
沸石基催化剂在全球范围内广泛应用于许多工业过程，如原油精炼和大宗化学品生产。在这项工作中，通过傅里叶变换红外光谱（FTIR）在线研究，深入研究了低密度聚乙烯（LDPE）的裂化过程，以考察具有不同织构特征的纯微孔沸石的催化效率。为了提供关于所研究沸石的催化活性的补充和有价值的信息，将热重分析（TGA）结果与在操作条件下生成的产物产率进行了比较。通过气相色谱-质谱联用（GC-MS）分析反应产物，以确定烃链分布，包括烷烃、烯烃和芳烃。评估了结构和酸性参数对催化参数的个别影响。沸石中高强度桥接羟基的积累有利于降低聚合物分解温度。通过对纯微孔沸石的策略性比较，我们表明 LDPE 的催化裂化主要由微孔环境固有的酸性特征决定。
