As β-pinene is one of the main compounds of turpentine oil, its epoxidation is of academic and industrial interest. In the present work, the activity of a low-cost calcium material and magnesium oxide was compared with that of hydrotalcites for the catalytic epoxidation of β-pinene. FTIR, XRD, nitrogen adsorption/desorption isotherms, BET and TPD-CO2 analyses were used for identifying the influence of basicity and textural properties of the materials on β-pinene epoxidation. Materials with medium-strength basic sites showed the highest activity; a complete conversion of β-pinene and 74% selectivity towards β-pinene epoxide was reached over magnesium oxide. A mechanism for this reaction over magnesium oxide is proposed based on the deprotonation and hydration of the catalyst, which favored the formation of an intermediate oxidant and the activation of the substrate. Purification of the reaction product by filtration, liquid–liquid extraction, drying and simple distillation leads to a final β-pinene epoxide concentration higher than 90% wt; the stability of the epoxide was verified by measuring its composition during 20 days.

中文翻译：

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用高活性低成本催化剂环氧化β-蒎烯

由于β-蒎烯是松节油的主要化合物之一，其环氧化具有学术和工业意义。在目前的工作中，将低成本钙材料和氧化镁的活性与水滑石的活性进行了比较，用于 β-蒎烯的催化环氧化。FTIR、XRD、氮吸附/解吸等温线、BET 和 TPD-CO2 分析用于确定材料的碱度和质构特性对 β-蒎烯环氧化的影响。具有中等强度碱性位点的材料表现出最高的活性；β-蒎烯的完全转化率和对 β-蒎烯环氧化物的选择性在氧化镁上达到了 74%。基于催化剂的去质子化和水合，提出了该反应在氧化镁上的机制，这有利于中间氧化剂的形成和底物的活化。通过过滤、液液萃取、干燥和简单蒸馏对反应产物进行纯化，使最终的 β-蒎烯环氧化物浓度高于 90% wt；通过在 20 天内测量其组成来验证环氧化物的稳定性。