摘要
用柠檬酸法结合浸渍法制备了一系列负载WOx的Co-Fe-Mo-O复合氧化物催化剂.利用X射线衍射、Ramam光谱、X射线光电子能谱和BET比表面积等技术表征催化剂,在固定床反应器上考察了催化剂催化CH4氧化反应的性能.实验结果表明,适量的Fe(n(Fe):n(Co)=(0～1):9)掺杂到CoMoO4中,对Co-Mo-O骨架产生影响,氧化钨以无定形WO3的形式分布于催化剂表面.WOx/Co1-yFeyMo-O催化剂对CH4氧化反应具有催化活性,随着Co1-yFeyMo-O中Fe3+掺杂量的增加,产物CO的选择性增加,Co1-yFeyMo-O上负载氧化钨后,CO选择性也增加.WOx/Co0 9Feo.1Mo-O,WOx-(Co0.9Fe0.1Mo-O)(柠檬酸一步法得到),WOx/Co0.8Fe0.2Mo-O催化剂还具有一定的CH4氧化生成甲醇/甲醛的选择性.Co1-yFeyMo-O催化CH4氧化生成合成气的性能优于生成甲醇/甲醛的性能.
A series of Co -Fe -Mo -O composite oxide catalysts supported with WOx were prepared by citric acid sol - gel method and followed by aqueous impregnation. XRD, Raman, XPS and BET methods were used to characterize the catalysts. The partial oxidation of methane was carried out in a continuous flow fixed - bed reactor. The addition of appropriate amount of Fe into CoMoO4 to form Co1-yFeyMo -O（ y ≤0.1 ）affected the framework of Co - O - Mo. Amorphous WO3 was found to be formed on surface of catalysts. Co1-yFeyMo - O and WOx/CO1-yFeyMo -O catalysts showed activity for partial oxidation of methane. With increase of Fe^3＋ content in Co1-yFeyMo - O composite oxides, CO selectivity increased, and CO2 selectivity decreased. When WO/ was supported on CO1-yFeyMo- O as catalyst, no obvious change of CH4 conversion was observed, but CO selectivity also increased and CO2 selectivity decreased. The formation of methanol/formaldehyde was found when WOx/Coo. 9 Fe0.1 Mo - O, WOx - （ Co0. 9 Fe0.1 Mo - O） （ prepared by one step aqueous impregnation method） and WOx/Co0. 8Fe0. 2Mo -O catalysts were in operation. It seemed that CH4 could be oxidized more easily to H2/ CO than to CH3OH/CH20 over Co1-yFey -Mo -O.
出处
《石油化工》
EI
CAS
CSCD
北大核心
2005年第12期1134-1139,共6页
Petrochemical Technology
基金
中国科技部"973"项目(2005CB221401)
关键词
甲烷
催化氧化
钼酸盐
氧化钨
一氧化碳
二氧化碳
甲醇
甲醛
催化剂
methane
catalytic oxidation
molybdate
tungstic oxide
carbon monoxide
carbon dioxide
methanol
formaldehyde
catalyst
