In this work, different magnesium silicate mineral samples based on antigorite, lizardite, chrysotile (which have the same general formula Mg₃Si₂O₅(OH)4), and talc (Mg₃Si₄O₁₀(OH)₂) were reacted with KOH to prepare catalysts for biodiesel production. Simple impregnation with 20wt% K and treatment at 700-900°C led to a solid-state reaction to mainly form the K₂MgSi0₄ phase in all samples. These results indicate that the K ion can diffuse into the different Mg silicate structures and textures, likely through intercalation in the interlayer space of the different mineral samples followed by dehydroxylation and K₂MgSi0₄ formation. All the materials showed catalytic activity for the transesterification of soybean oil (1:6 of oil: methanol molar ratio, 5wt% of catalyst, 60°C). However, the best results were obtained for the antigorite and chrysotile precursors, which are discussed in terms of mineral structure and the more efficient formation of the active phase K₂MgSi0₄.

中文翻译：

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具有不同结构和形态的天然镁硅酸盐：与K反应生成K 2 MgSiO 4催化剂，用于生产生物柴油

在这项工作中，分别使用了基于蛇纹石，蜥蜴石，温石棉（具有相同的通式Mg ₃ Si ₂ O ₅（OH）4）和滑石粉（Mg ₃ Si ₄ O ₁₀（OH）₂）的不同硅酸镁矿物样品。与KOH反应制备用于生产生物柴油的催化剂。用20wt％的K进行简单的浸渍并在700-900°C的温度下处理会导致固态反应，主要形成K ₂ MgSiO ₄所有样品的相。这些结果表明，K离子可以扩散到不同的Mg硅酸盐结构和织构中，可能是通过插入不同矿物样品的层间空间，然后进行脱羟基和形成K ₂ MgSiO ₄。所有材料均显示出对大豆油酯交换反应的催化活性（油：甲醇的摩尔比为1：6，催化剂的5wt％，60°C）。但是，对于蛇纹石和温石棉前体，获得了最佳结果，这些矿物，矿物结构和活性相K ₂ MgSiO ₄的更有效形成方面进行了讨论。