Zr-SBA-15-SO3H固体酸催化剂的制备、表征及催化酯交换制备生物柴油

Preparation and characterization of Zr-SBA-15-SO3H solid acid catalyst and its catalytic transesterification to prepare biodiesel

以SBA-15为载体,采用共缩合-水热法制备Zr-SBA-15,通过化学接枝法引入磺酸基团进行改性,得到Zr-SBA-15-SO3H固体酸催化剂。采用X射线衍射、傅里叶红外光谱、N2吸附-脱附、热重分析、扫描电镜和透射电镜对催化剂的结构进行表征。以棕榈油和甲醇的酯交换反应为探针,测试Zr-SBA-15-SO3H的催化性能。结果表明:掺杂Zr的SBA-15磺酸官能化后得到的Zr-SBA-15-SO3H固体酸催化剂具有较强的酸性,且保持了SBA-15的原有形貌及介孔结构;在反应温度130℃、反应时间4 h、催化剂用量8%、醇油摩尔比35∶1的反应条件下,生物柴油收率超过93%,且制备的催化剂循环使用4次后仍具有较高的催化性能,生物柴油收率仍保持在75%以上。

Zr-SBA-15 was prepared by co-condensation-hydrothermal method with SBA-15 as supporter,then sulfonic acid group was introduced for modification by chemical grafting to obtain Zr-SBA-15-SO3 H solid acid catalyst.The structure of the catalyst was characterized by XRD,FT-IR,N2 adsorption-desorption measurement,thermogravimetric analysis,SEM and TEM.The catalytic performance of Zr-SBA-15-SO3 H was tested by transesterification of palm oil and methanol.The results showed that Zr doped SBA-15 had strong acidity after sulfonic acid functionalization and maintained the original morphology and mesoporous structure of SBA-15.The biodiesel yield exceeded 93%under the conditions of reaction temperature 130℃,reaction time 4 h,catalyst dosage 8%and molar ratio of methanol to palm oil 35∶1.The catalyst prepared still had higher catalytic activity with the biodiesel yield above 75%after four cycles of recycling.