Synthesis And Performance Research Of The New Nanoscale Cu Base Catalyst

Being a fundamental material in C1 industries,methanol is widely used in organic synthesis,dyes,pesticides,paint,national defense and other industrial fields.Recently,with the development of science and technology,the application of methanol is expanding continuously.It has become a potential vehicle fuels and fuel-cell fuels.At the same time,being a country rich in coal and poor in oil resources,primary energy with coal-based will continue long-term sustainability.The shortage of liquid fuels,such as gasoline and diesel fuel will become increasingly serious.Therefore,the development of alternative fuels,especially coal-based clean alternative fuel is imperative.It is feasible to develop coal-based alcohols?mainly methanol?as alternative fuels in China.Since the 1960s',the research of methanol synthesis catalysts has attracted great attention.In spite of industrialized process,there still exist many drawbacks of copper-based catalysts.The reaction mechanism,reaction thermodynamics and dynamics of hydrogenation of carbon monoxide were analyzed.Using the coprecipitation method to prepare catalyst samples of different content of Cu,ratio of Zn/Al and content of additive Mn,the catalytic performance of Cu-based catalysts for methanol synthesis from CO hydrogenation were evaluated by fixed bed reactor.Characterizations of physical and chemical properties of the catalysts were investigated by XRD,BET,H₂-TPR,NH3-TPD,SEM,TEM and FTIR.The effects of different preparation parameters on catalytic activity of catalysts were studied.The results show that under the conditions of 1:2:2:0.05 of Cu/Zn/Al/Mn molar ratio,the low frequency of 22 kHz and high frequency of 40 kHz ultrasonic processing,1.5mol/L of solution concentration,7.5 of pH,550 ? of calcination temperature,7h of calainating time,the catalytic activity is excellent.The main factors that influenced the reaction process are the reaction pressure,temperature,space velocity,ratio of hydrogen and carbon monoxide,when combined with reaction thermodynamics and dynamics.By evaluating the activity of catalyst and analyzing the factors of hydrogenation,the optimal reaction conditions are as follows:250? of reaction temperature,6.0MPa of reaction pressure,2.5 of ratio of hydrogen and carbon monoxide,5000h-1 of space velocity.The conversion of carbon monoxide and selectivity of methanol was98.50% and 96.51% under the optimized reaction conditions,and the catalyst showed stable performance and long service life.