The use of waste tires for producing valuable chemicals via fast pyrolysis necessarily involves the understanding and synthesis of catalysts. Therefore, here, a statistical-based screening of SiO₂-supported metal catalysts (Ni, Pd, Co, and Fe) to produce limonene from waste tire pyrolysis (WTP) is presented. The response surface method (RSM) was integrated into a principal component analysis (PCA) to identify the catalyst and reaction conditions that maximize the limonene yields for the experiments performed in an analytical pyrolyzer. The experiments were performed in an analytical pyrolysis unit coupled to a mass spectrometer (Py-GC/MS) using the temperature, the tire-to-catalyst ratio, and the type of catalyst as independent variables. The samples were grouped using PCA into 4 clusters according to the studied experimental conditions. The RSM model demonstrates that Co/SiO₂ generates the most positive influence on the selectivity towards limonene under the following operating conditions: 370 °C and a tire-to-catalyst ratio of 1:5. Furthermore, it is possible to maintain a high selectivity to limonene and reduce the optimal catalyst load by slightly increasing the reaction temperature.

Graphical abstract

中文翻译：

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通过催化快速热解从废轮胎生产柠檬烯：基于统计的镍、钯、钴和铁负载催化剂的筛选

使用废轮胎通过快速热解生产有价值的化学品必然涉及对催化剂的理解和合成。因此，在这里，基于统计的 SiO _2筛选介绍了从废轮胎热解 (WTP) 中生产柠檬烯的负载型金属催化剂（Ni、Pd、Co 和 Fe）。响应面法 (RSM) 被集成到主成分分析 (PCA) 中，以确定在分析热解器中进行的实验中最大化柠檬烯产率的催化剂和反应条件。实验是在与质谱仪 (Py-GC/MS) 耦合的分析热解装置中进行的，使用温度、轮胎与催化剂的比例以及催化剂的类型作为独立变量。根据研究的实验条件，使用 PCA 将样品分为 4 个簇。RSM 模型表明 Co/SiO ₂在以下操作条件下对柠檬烯的选择性产生最积极的影响：370 °C 和 1:5 的轮胎催化剂比。此外，可以通过稍微提高反应温度来保持对柠檬烯的高选择性并降低最佳催化剂负载量。

图形概要