混合法制备Co-Mo/MgO-Al_2O_3变换催化剂的XRD和TPR表征  

XRD and TPR Characterization of the Catalyst Co-Mo/MgO-Al_2O_3 Prepared by Mixing-Kneading Method for Water Gas Shift

作　　者：郑泉兴[1] 王琪[1] 宋建华[1] 李一农[1] 陈汉宗[1] 方维平[1] 杨意泉[1] 

机构地区：[1]厦门大学化学化工学院物理化学研究所固体表面物理化学国家重点实验室,福建厦门361005

出　　处：《厦门大学学报（自然科学版）》2004年第6期820-823,共4页Journal of Xiamen University：Natural Science

基　　金：福建省百千万人才工程(闽人办[2003]40号);厦门市科技创新基金(3502Z20031082)资助

摘　　要：用混合煅烧法制备的Co Mo/MgO Al2O3一氧化碳变换催化剂,在2.0MPa及多种汽气比条件下与同类型催化剂进行活性评价比较,达到德国催化剂K8 11的活性水平.对催化剂及参比样MoO3/Al2O3、MoO3/MgO Al2O3和MgO Al2O3等进行XRD或TPR表征,结果显示Co Mo/MgO Al2O3催化剂存在MoO3、CoMoO4、MgMoO4和MgAl2O4等物种,单纯的Mo在MgO Al2O3载体上分散度比在γ Al2O3载体上低,MoO3的结晶度较高,其还原温度提高;添加Co后,MoO3的分散度得到提高.在Co Mo/MgO Al2O3催化剂的TPR谱中出现属于MoO3(624℃)和CoMoO4(805℃)的两个还原峰,该催化剂对CO变换活性的提高与CoMoO4相的生成密切相关.The catalyst Co-Mo/MgO-Al_2O_3 for the reaction of WGS(water gas shift) was prepared by means of mixing-kneading method of raw materials.The result shows that the activity of the catalyst reach the level comparable to that of K-811 catalyst developed by German under 2.0 MPa and the same ratio of water gas.The results of XRD and TPR characterization of the catalyst and reference samples MoO_3/Al_2O_3,MoO_3/MgO-Al_2O_3 and MgO-Al_2O_3 show that the species of MoO_3,CoMoO_4,MgMoO_4,MgAl_2O_4 co-existed in the catalyst Co-Mo/MgO-Al_2O_3.On the reference samples,Mo species on support MgO-Al_2O_3 was found to be less dispersive in comparison with γ- Al_2O_3,therefore the particle of MoO_3 with high crystal side may grow up,giving rise to higher reduction temperature.While after the addition of Co to Mo/MgO-Al_2O_3 the dispersion of MoO_3 on the carrier was found to be improved.Meanwhile in the TPR spectra of the catalyst Co-Mo/MgO-Al_2O_3,two hydrogen-consumed peaks at 624℃ and 805℃ were recorded,which can be attributed to reduction of MoO_3 and CoMoO_4 respectively.The experiment results show that the phase CoMoO_4 in the catalyst Co-Mo/MgO-Al_2O_3 was found to be responsible for the improvement of the activity for the reaction of WGS.

关 键 词：γ-Al2O3 变换催化剂 CO-MO MOO3 TPR 活性评价 变换活性 表征 XRD 分散度 

分 类 号：N941.5[自然科学总论—系统科学] O643[理学—物理化学]