无定形态P_2O_5-V_2O_5负载型多级孔催化材料的制备及催化合成丙烯酸甲酯  

Preparation of Amorphous P_2O_5-V_2O_5 Multilevel Porous Structure Catalytic Materials and Its Catalytic Synthesis of Methyl Acrylate

作　　者：宋伟明[1] 荆涛[1] 田景芝[1] 

机构地区：[1]齐齐哈尔大学化学与化学工程学院,黑龙江齐齐哈尔161006

出　　处：《化学反应工程与工艺》2014年第6期536-543,共8页Chemical Reaction Engineering and Technology

基　　金：黑龙江省自然科学基金(B201010)

摘　　要：分别以层析硅胶和大孔Si O2为载体,制备了负载型P2O5-V2O5催化剂,通过透射电镜(TEM)、N2物理吸附、X射线光电子能谱(XPS)以及X射线衍射(XRD)等分析表征了催化剂的形貌和结构,并在固定床微反实验装置上,研究了不同载体的催化剂对醋酸甲酯与甲缩醛合成丙烯酸甲酯的催化性能。结果表明:以大孔Si O2为载体的磷钒催化剂具有均匀有序的大孔和介孔结构;当催化剂活性组分磷钒原子比为1.03时,磷钒以(VO)2P2O7为主;磷钒原子比为2.60时,表面活性组分磷钒为无定形态,在V物种中明显增加了V5+的比例,有助于促进V4+和V5+的协同作用,对羟醛缩合反应具有很好的促进作用;在磷钒原子比为2.60:1的情况下,以大孔Si O2为载体的P2O5-V2O5催化剂比层析硅胶为载体的催化剂具有更好的催化性能。The P2O5-V2O5 catalysts were prepared by using chromatography silica gel and macroporous SiO2 as carriers, respectively. The morphology and structure of the catalysts were characterized by transmittance electron microscopy （TEM）, N2 adsorption-desorption, X-ray photoelectron spectroscopy （XPS） and X-ray diffraction （XRD）. The effects of different carriers on the catalytic performance were studied by the synthesis of methyl acrylate from methyl acetate and methylal in a fixed bed reactor. The results showed that the P2O5-V2O5 catalyst with macroporous SiO2 as carrier possessed uniformly ordered macroporous/mesoporous structure, and the active component of V2O5-P2O5/SiO2 catalyst with molar ratio of phosphor to vanadium 1.03 was （VO）2P2O7; V2O5-P2O5/SiO2 catalyst was amorphous structure with molar ratio of phosphor to vanadium was 2.60, possessing more V^5＋, which promoted the synergistic action of V^4＋ and V^5＋ and the aldol reaction. When molar ratio of phosphor to vanadium was 2.60, the P2O5-V2O5 catalyst with macroporous SiO2 as carrier had better catalytic performance than that with chromatography silica gel as carrier.

关 键 词：磷钒催化剂 多级孔 丙烯酸甲酯 羟醛缩合 

分 类 号：TQ426.61[化学工程] O643.38[理学—物理化学]