Sulfonated carbon is a green, solid acid catalyst but its surface area, separation, and recovery after utilization need to be improved. The objective of the present study was to provide an environmentally friendly and economical method to prepare magnetic sulfonated carbon composite catalyst with a large surface area using palygorskite (Plg) as the support. A magnetic sulfonated carbon/Fe₃O₄/Plg composite catalyst was prepared via simultaneous calcination and sulfonation of the mixture of source, p-toluenesulfonic acid (TsOH), and Fe₃O₄/Plg. Fe₃O₄ nanoparticles and Plg nanorods were encased by a carbon layer derived from sucrose and TsOH. The composite catalyst exhibited good magnetic properties and high catalytic performance for the esterification of oleic acid with methanol. Oleic acid conversion reached 88.69% after the first catalytic cycle. Plg nanorods replaced sucrose and increased the catalyst’s surface area. The introduction of Fe₃O₄ nanoparticles improved further the acid content and oleic-acid conversion and achieved 70.31% after five cycles. The catalyst was recycled easily using an external magnetic field and its magnetic property remained unchanged due to the protection of the carbon layer.

磺化碳是一种绿色的固体酸催化剂，但其表面积、分离度和利用后的回收率有待提高。本研究的目的是提供一种环境友好且经济的方法，以坡缕石（Plg）为载体制备大表面积的磁性磺化碳复合催化剂。通过源、对甲苯磺酸(TsOH)和Fe ₃ O ₄ /Plg的混合物同时煅烧和磺化制备磁性磺化碳/Fe ₃ O ₄ /Plg复合催化剂。铁₃ O ₄纳米粒子和 Plg 纳米棒被源自蔗糖和 TsOH 的碳层包裹。该复合催化剂对油酸与甲醇的酯化反应表现出良好的磁性和较高的催化性能。第一次催化循环后油酸转化率达到88.69%。Plg 纳米棒取代了蔗糖并增加了催化剂的表面积。Fe ₃ O ₄纳米颗粒的引入进一步提高了酸含量和油酸转化率，5个循环后达到了70.31%。该催化剂易于利用外部磁场回收，并且由于碳层的保护，其磁性保持不变。