【摘要】 在流化床管式炉中,通过对废山茶油壳进行高温炭化处理制备了一种碳基材料。以该碳基材料为载体,并对其进行稀土金属离子钕和硫酸磺化改性,合成了一种新型碳基固体酸催化剂SO₄^2-/Nd₂O₃/C。对制备而成的催化剂进行了多种物理化学表征分析,并以其为经甲醇和油酸酯化反应来合成生物柴油的催化剂,对其催化活性和稳定性进行了研究。结果表明,当甲醇和油酸物质的量比为2∶1,催化剂与反应物质量比为2%,反应时间为120 min,反应温度为90℃,油酸的转化率为96.70%。催化剂经循环使用三次后,油酸的转化率仍高达86.74%。高催化活性可归因如下:由于Nd、O、S元素的电负性分别为1.14、3.44和2.58,因而Nd易向O和S元素的2p空轨道提供孤对电子,使Nd³⁺与SO₄^2-之间形成稳定的配位键。并且,由于S=O键具有强吸电子作用,而导致了与SO₄^2-配位的Nd³⁺所产生的静电场增大,当有水（强配体）存在时,可使SO₄^2-/Nd₂O₃/C催化剂呈现出强Brnsted酸性。更多还原

【Abstract】 A carbon material was prepared from the high temperature carbonization of waste camellia seed shell in a fluidized bed tubular reactor. The carbon material was applied as the catalyst support to prepare a newcatalyst SO₄²/ Nd₂O₃/ C after it was simultaneously modified by Nd³⁺and sulfonated by concentrated sulfuric acid through impregnation method. The catalyst was characterized by several physical and chemical characterization methods. The catalytic activity and reusability of SO₄^2-/ Nd₂O₃/ C were evaluated using it to catalyze the esterification of methanol and oleic acid for the synthesis of biodiesel. Results showed that the conversion of oleic acid was 96. 70% when the methanol / oleic acid molar ratio was 2 ∶ 1,reaction temperature was 90 ℃,and catalyst / reactants was 2% under reflux condensation for 120 min. After recycling of three times,the conversion of oleic acid was still 86. 74%. High activity can be explained as follows: the electro-negativity of Nd is 1. 14,which is smaller than O（ 3. 44） and S（ 2. 58）,so it will provide lone electron pair to the empty2 p orbit of O and S,resulting in the formation of a stable coordination bond between Nd³⁺and SO₄^2-. In addition,S = O double bond can induce a strong electron withdrawing effect,which can increase the electrostatic field of Nd³⁺when it was coordinated with SO₄^2-. And finally,it should be noticed that H₂O is a strong ligand.Hence,SO₄^2-/ Nd₂O₃/ C exhibited a strong Brnsted acidity when H₂O existed in the reaction medium.更多还原