Study On The Precursor Of Catalysts For The Synthesis Of Methanol And Ethanol By Complete Liquid Phase Technology

As fossil fuel diminished and the price of crude oil rise rapid,energy problem become more and more serious.The research of clean fuel is a matter of great urgency.Methanol and ethanol are tradition alternative fuels which have broad application and quite much same chemical energy with petrol.Besides its can lessen greenhouse gas and other pollutants emission.So produce syngas(H2 and CO)via coal gasification,then translate into methanol and ethanol ect clean fuels have important significance.In our previous work,it had been found that Cu-Zn-Al synthesis methanol catalysts prepared by complete liquid-phase method which invent by our group accompany with high ethanol.But it is difficult to reproduce,indicating that we have not completely master the key technique of complete liquid phase method.In this paper,The catalysts were prepared by different H2O/AIP?Al content?adding ways and Co assistant based on the study above was investigated,These catalysts were characterized by XRD?H2-TPR?NH3-TPD?BET?XPS and relate with test of catalysts in order to ascertain essential factor of complete liquid phase technique,the main experimental conclusions are as follows:1.The catalysts with different ratio of H2O/AIP have significant influence on the catalysts performance,the catalysts prepared with H20/AIP= 60 showed best CO conversion nearly reached 38%,but the selectivity of alcohols showed little difference.2.The catalyst prepared with the solution of Cu(NO3)2 and Zn(NO3)2 drop into A1 sol showed best CO conversion,while catalysts prepared through adding(C3H7O)3A1 into the solution of Cu(N03)2 and Zn(N03)2 had excellent the selectivity to ethanol at beginning stage,nearly reaching 40%.But it decreased sharply as time on stream,only 5%when on the fifth day.3.The research indicated that the synthesis of ethanol not only need higher Cu/Zn ratio,but also need higher Cu species in oxidation state.However,the synthesis of methanol may need higher Cu0 species in Cu component.4.The Cu species have strong interaction with zinc oxide or aluminum-oxide,and the more difficult is the reduction of the catalyst,the higher the selectivity of ethanol.5.The activity of catalysts decreased as A1 content increased,but it was good for its stability.Increase or decrease A1 content were not benefit for the synthesis of alcohols,the catalysts with the ratio of Cu:Zn:Al = 2:1:0.8 had the most highest selectivity of alcohols.6.The assistant of Co is not good for the synthesis of alcohols.The catalysts with a amount of Co will restrain the synthesis of alcohols and more Co dosage will promote the generate of hydrocarbons.