This study investigates the cracking of waste engine oil (WEO) using bentonite clay (BC) activated through acid and thermal methods, as well as with Zn-doped BCs. Acid activation with 1 M HCl and Zn doping did not alter the BC catalyst’s structure. XRD and SAED analyses confirmed the crystallinity, while TEM showed partial destruction of the layered structure. XRF analysis indicated reduced Al and Si content upon Zn-doping due to high cation exchange capacity. Zn-doping decreased surface area and pore volume but increased acidic sites in acid-treated catalysts, although Zn suppressed these sites in calcined BC. Zn-doped catalysts displayed higher thermal stability. Cracking WEO at 450 °C for 45 min, with and without catalysts, yielded high liquid product recovery (72.6 %–82.8 %), primarily carboxylic acids and aromatics. This demonstrates the potential of Zn-doped BC as an effective catalyst for converting WEO into valuable products, aiding waste management and resource utilization.

中文翻译：

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用于废机油裂解的掺锌膨润土催化剂：热处理提供了酸活化的更清洁替代方案


本研究研究了使用酸法和热法活化的膨润土 (BC) 以及掺锌 BC 来裂解废机油 (WEO)。用 1 M HCl 和 Zn 掺杂进行酸活化不会改变 BC 催化剂的结构。 XRD 和 SAED 分析证实了结晶度，而 TEM 显示层状结构部分破坏。 XRF 分析表明，由于高阳离子交换容量，Zn 掺杂后 Al 和 Si 含量降低。锌掺杂降低了表面积和孔体积，但增加了酸处理催化剂中的酸性位点，尽管锌抑制了煅烧BC中的这些位点。 Zn掺杂催化剂表现出更高的热稳定性。在使用或不使用催化剂的情况下，WEO 在 450 °C 下裂解 45 分钟，产生了高液体产物回收率 (72.6%–82.8%)，主要是羧酸和芳烃。这证明了掺锌BC作为有效催化剂的潜力，可将WEO转化为有价值的产品，有助于废物管理和资源利用。