二氧化碳和丙烯直接合成甲基丙烯酸NiPMo_(12)催化剂的研究

Studies on NiPMo_(12) Catalyst for Direct Synthesis MAA from Propylene and Carbon Dioxide

用硝酸镍对磷钼酸 ( MPA)进行改性制得 Ni PMo1 2 催化剂 .采用 ICP,XRD,TG-DTA,EXAFS,IR,TPD-MS和微反技术研究了催化剂的化学组成、分子结构、化学吸附性质和催化反应性能 .3 5 0℃下Ni PMo1 2 催化剂仍保持原有的 Keggin结构 .CO2 在 Lewis酸位 Ni( )和 Lewis碱位 Ni— O— Mo的桥氧协同作用下可生成 CO2 桥式吸附态 Ni( )← O— ( CO)— ( O- — Ni) .丙烯在催化剂上存在多种吸附态 .在氢转移和碳插入作用下得到了反应产物 MAA.在 2 90℃和 1 MPa的反应条件下 ,丙烯的摩尔转化率为 2 .6%,产物 MAA选择性为 96%.

NiPMo 12 catalyst was prepared by using the reaction of MPA and nickel nitrate. The chemical composition, molecular structure, chemisorption character and reaction behaviour were studied by different techniques including inductively coupled plasma atomic emission spectroscopy, X ray diffraction, thermogravimetric analysis, infrared spectrum analysis, extend X ray absorption fine structure, temperature programmed desorption and microreactor, respectively. At 350 ℃, the catalyst still remained the or...