Preparation And Reaction Performance Of Catalyst For Methanol Synthesis From CO₂/H₂

Methanol is a kind of important organic chemical product and environmental additive for fuel. It can be widely applied in organic synthesis, fuel, medicine, coating and military industry etc. The carbon source can be recycled and the chemical materials can be simoultaneously supplied via methanol synthesis from CO₂/H2. The key factors to achieve above process is development of higher efficent catalyst.Cu/ZrO₂ catalysts were respectively prepared via fractional precipitation(FP), deposition coprecipitation (DP) and solid-state reaction(SR) methods. The samples were characterized by N2 adsorption-desorption, XRD, TPR, In-situ IR and XPS techniques. Reaction performances of the catalysts were also studied. The results showed that the physical structures, reduction properties and reaction performances of Cu/ZrO₂ are greatly influenced by preparation methods. The surface area and reduction tempareture of catalysts prepared by FP and SR methods are higher than catalysts prepared by DP methods. While the DP catalysts possess the smallest pore diameter and the strongest interaction between Cu and ZrO₂. In addition, the main factor to affect the catalyst performance is the interaction between Cu and ZrO₂ rather than the surface area of the catalyst. The interaction between Cu and ZrO₂ is stronger, the reduction temperature is lower and the reaction performance is better.In order to improve the reaction performance and stability of the catalysts, MnO₂, Al2O3 and B2O3 are respectively introduced to the catalysts. It is found that the activity of catalysts is increased after introduction of promotors. Of interest is the methanol selectivity is fluctuated with the different promoter. The selectivity is decreased owing to the addtion of B2O3. On the contrary, selectivity is increased after introducing Al2O3. Space time yield of CuO/Al2O3/ZrO₂ is also the highest. Of note is that effect of MnO₂ on the reaction performance is not much clearer than Al2O3 and B2O3 .In additon, the main operating conditions for the methanol synthesis from CO₂/H2 were optimized, including reduction tempareture, reaction tempareture, pressure and space velocity. The results showed that the effect of reaction conditions on catalyst performance is consistent with the reported.