Controlled Synthesis Of Copper-Manganese Oxide Catalyst For Water Gas Shift Reaction

The performance of copper manganese mixed oxides catalyst for water gas shift reaction (WGSR) is determined by the preparation method and technology conditions. The texture of precursor of the catalyst is absolutely determined by the reaction crystallization process. Different precursor formed in the precipitation process lead to final catalyst sample with different texture and catalytic performance. In this thesis, the co-precipitation was used to the preparation of copper manganese mixed oxides catalyst for WGSR and the characteristics of the catalysts were studied by XRD, BET,Micro-Reactor-chromatography. The emphasis of this thesis is to speculate the dependence of catalytic performance and thermal-stability on the catalyst texture influenced by precipitator species, precipitator proportion, drop wise order of precipitator and the quantity of alkali used in the precipitation reaction.The species and proportion of precipitator has crucial effect on catalyst performance and texture of catalyst. The process of K-Cu precipitation, the dried sample form Cu4+2SO4(OH)6·2H2O crystalline phase at pH values from 6 to 12,whereas, the dried sample form Cu4+2SO4(OH)6·2H2O crystalline phase at pH values from 6 to 10 and the sample crystalline is CuO when pH value reaches 12.2 in the process of Na-Cu precipitation. At 250℃after heat-resistance, the activity of the sample which prepared by Na93K7 precipitator is 74.31%,it is the finest one in all samples.Drip the precipitator in different order can affect catalytic performance and thermo-stability of catalyst. At 250℃after heat-resistance, the activity sequence of sample which prepared in different dropwise order at 550℃calcined is Na-Cu K-Mn>K-Cu Na-Mn= Na1K2>K1Na2. At 1000℃calcined,the sequence is Na-Cu K-Mn=K-Cu Na-Mn= Na1K2>K1Na2.The quantity of alkali used in the precipitation reaction crucial effect on catalytic performance and thermo-stability of catalyst. When the amount of alkali is in certain scope,dried sample form CuO and Mn3O4 crystalline phase,solid solution spinel Cu1.5Mn1.5O4 form after calcined,and then deoxidized sample is MnO和Cu. OH-/M2+=2.1048 is the best choice with NaOH as precipitator, on the other hand OH-/M2+= 2.1148 is the best choice with KOH as precipitator.