摘要
通过程序升温还原磷钼酸盐前体的方法制备了无负载磷化钼 (MoP)催化剂 ,并采用XRD ,BET ,XPS和高压连续微反技术 ,考察了催化剂的性质 ,研究了还原温度对催化剂HDN ,HDS和HYD性能的影响 .结果表明 ,在还原温度为 6 0 0～ 80 0℃范围内 ,成功制备出磷化钼催化剂 .高压连续微反结果表明 ,MoP的催化特性与其比表面积、还原度和表相组成有关 ,比表面积大、还原度适中和表相Moδ+ /Pδ -比适中的磷化钼具有更高的催化活性 ;6 5 0～ 70 0℃为最合适的还原温度 ,高于或低于该温度时所制备的MoP催化剂活性均大幅度下降 .在合适的条件下 ,MoP催化剂对噻吩HDS ,吡啶HDN和环己烯HYD的转化率可分别达到 94 3% ,10 0 0 %和 90 3% .
A series of unsupported molybdenum phosphide were prepared at different reduction temperatures by temperature-programmed reaction ( TPR) process. The phosphate precursor was prepared as follows: (NH4)(6)Mo7O24 . 4H(2)O and (NH4)(3)PO4 . 3H(2)O were dissolved in distilled water; the clear solution was stirred overnight, and then was heated to evaporate water; the resulted material was dried at 120 degreesC for 6 h, then calcined at 500 degreesC for 6 h. The phosphate precursor was transformed to the final product by TPR that is the main step for the preparation of MoP catalyst. The prepared Mol? catalyst was characterized by XRD, BET and XPS techniques. The catalytic activity for hydrodesulfurization of thiophene, hydrodenitrogenation of pyridine and hydrogenation of cyclohexene was measured in a continuous microreactor. The results indicated that the catalyst prepared by reduction at 650similar to700 degreesC was the most active one. The catalytic activity was related to the surface area, reduction degree and surface component, and a catalyst with largest surface area, moderate reduction degree and suitable surface component was most effective. The conversion of thiophene, pyridine and cyclohexene could reach 94.3%, 100.0% and 90.3%, respectively.
出处
《催化学报》
SCIE
CAS
CSCD
北大核心
2005年第1期65-68,共4页
基金
国家自然科学基金资助项目 (2 0 2 73 0 11)
国家重点基础研究发展规划项目 (G2 0 0 0 0 480 0 3 )
关键词
磷化钼
程序升温还原
加氢脱硫
加氢脱氮
加氢精制
molybdenum phosphide
temperature-programmed reduction
hydrodenitrogenation
hydrodesulfurization
hydrofining
