AlPW_(12)O_(40)-SiO_(2)固体酸在生物柴油合成中的催化活性研究  

Study on catalytic activity of AlPW_(12)O_(40)-SiO_(2)solid acidin biodiesel synthesis

作　　者：王立勤 彭芹 丁钰妍 胡景铭 戴啸云 王锋[1] WANG Liqin;PENG Qin;Ding Yuyan;HU Jingming;DAI Xiaoyun;WANG Feng(Hunan City University,Key Laboratory of Low Carbon and Environmental Functional Materials of College of Hunan Province,Yiyang,Hunan 413000,China)

机构地区：[1]湖南城市学院低碳与环境功能材料湖南省普通高校重点实验室,湖南益阳413000

出　　处：《湖南城市学院学报（自然科学版）》2024年第4期60-66,共7页Journal of Hunan City University:Natural Science

基　　金：湖南省教育厅科研项目(22C0524);湖南省大学生创新创业训练计划项目(S202311527072)。

摘　　要：首先,以AlPW_(12)O_(40)为活性组分,通过浸渍法将其负载在SiO_(2)上制得AlPW_(12)O_(40)-SiO_(2)固体酸催化剂;然后,通过调整活性组份与载体的比例,制备不同活性组分负载量的催化剂,并研究其在生物柴油(甲醇和油酸酯化反应为模型反应)合成中的催化活性;最后,利用X射线衍射仪、傅里叶变换红外光谱及氮气吸附脱附对催化剂的结构进行表征,并采用间接滴定法测量催化剂的总酸量。结果表明:AlPW_(12)O_(40)-SiO_(2)催化剂具有介孔结构,且AlPW_(12)O_(40)高度均匀分散在SiO_(2)表面;随着活性组分负载量从5%增大到25%,催化剂的总酸量从0.134 mmol/g增至0.588 mmol/g,催化剂的活性也提高了,且当活性组分负载量为25%时,油酸的转化率最高,为83.46%,而当负载量增加至30%时,催化剂酸量降低为0.541 mmol/g,且催化活性下降。通过单一变量控制法得到最优负载量催化剂作反应条件,即:活性组分负载量为25%、反应催化剂用量为20 wt.%、醇油摩尔比为15꞉1、化学反应温度为75℃、反应时间为4 h,此时油酸转化率为97.26%。Firstly,the AlPW_(12)O_(40)/SiO_(2)solid acid catalyst was prepared by loading AlPW_(12)O_(40)on the SiO_(2)by impregnation method with AlPW_(12)O_(40)as active component.Then,the catalysts with different active component loadings were prepared by adjusting the ratio of the active component to the carrier,and their catalytic activity in the synthesis of biodiesel(esterification of methanol and oleic acid as a model reaction)was studied.Finally,the structure of the catalyst was characterized by X-ray diffractometer,Fourier transform infrared spectroscopy and nitrogen adsorption desorption,and the total acid amount of the catalyst was measured by indirect titration.The results indicated that AlPW_(12)O_(40)-SiO_(2)exhibited mesoporous structures,and AlPW_(12)O_(40)was uniformly dispersed on SiO_(2)surface.The catalytic activity of AlPW_(12)O_(40)-SiO_(2)increased with the increase of its total acid amount.When the loading amount of AlPW_(12)O_(40)increased from 5%to 25%,the total acid amount of the catalysts increased from 0.134 mmol/g to 0.588 mmol/g,and the activity of the catalyst also increased.When the loading of the active component was 25%,the conversion rate of oleic acid was the highest,which was 83.46%.When the loading amount of the active component increased to 30%,the total acid amount of the catalyst decreased to 0.541 mmol/g,and the catalytic activity decreased.The reaction conditions were optimized by the single variable control method.The results indicated that when the loading amount of active component was 25%,the amount of catalyst(based on oleic acid)was 20 wt.%,the molar ratio of methanol to oleic acid was 15∶1,the reaction temperature was 75,the reaction time was 4℃h,the oleic acid conversion was 97.26%.

关 键 词：生物柴油 AlPW_(12)O_(40) 二氧化硅 酯化反应 

分 类 号：TQ426[化学工程] TQ645