TPSR Study Of Cu-ZnO Catalyst CO/CO₂ Co-hydrogenation To Methanol

At present,the greenhouse effect is becoming more and more serious.It is increasingly necessary to convert CO₂ into other chemical products through the green measures of CO₂ resource utilization.As a kind of easy-to-store liquid fuel,methanol is mainly used in the industrial production of Cu O-Zn O-Al₂O₃ as the catalyst,and the H₂/CO/CO₂ mixture is used as the raw material gas for the low-pressure methanol synthesis.In the process of methanol synthesis,the catalysis of Cu and Zn has been studied in depth,but the surface reaction process of the catalyst under different atmospheres is not clear.In this paper,the influence of p H,precipitation temperature and aging time of the process parameters on the performance of Cu-Zn O catalyst was firstly studied.The optimum process parameters p H7,precipitation temperature 70?and aging time 2h were determined.Using the above process parameters,Cu-Zn O catalysts with different composition ratios and Cu-Zn O-Zr O₂ catalysts with different Zr contents were prepared.Based on the research of TPSR technology for gas adsorption and desorption on the surface of catalysts,the TPSR technology was applied to test the performance of adsorption,desorption of CO,CO₂,and H₂ on the surface of the catalyst and the reaction process on the surface of the catalyst using chemical adsorption and mass spectrometry.Research indicates:?1?In the H₂/CO₂ atmosphere,the catalyst with smaller Zn content and smaller Cu particle size has higher CO₂ conversion rate and methanol yield,while the catalyst with Cu/Zn=4.5/4.5 has a reverse moisture vapor reaction?CO₂+H₂?CO+H₂O?produces less CO,so the methanol is more selective.?2?In the atmosphere of H₂/CO,Cu content as the catalyst increased,CO conversion rate increased,while the catalyst with more Zn content can make the CO first generate more CO₂ and the CO₂ hydrogenate to generate methanol,to obtain higher Methanol yield and selectivity.?3?In CO+CO₂+H₂ atmosphere CO and CO₂ conversion rate were decreased,but the methanol yield increase,CO,CO₂ gas competing reaction,the Cu/Zn=3/6 catalyst has the largest methanol selectivity,reaction by CO water vapor generated CO₂ further hydrogenation of methanol synthesis.?4?In H₂/CO₂ atmosphere,the 6%Cu-Zn O-Zr O₂ catalyst has higher CO₂ conversion and methanol yield,and Cu-Zn O-Zr O₂ catalyst with 6%Zr content reacts inversely to water vapor?CO₂+H₂?CO+H₂O?produces less CO,so methanol selectivity is also higher.Under the H₂/CO atmosphere,the particle size of Cu with 6%Zr content is small,which makes CO first generate more CO₂ through water vapor reaction,and then CO₂ is used as carbon source to hydrogenate to produce methanol,to obtain higher methanol yield and selectivity of methanol.Compared with CO/CO₂/H₂atmosphere,CO and CO₂ conversion ratios decreased,indicating that CO and CO₂gases compete with each other in the reaction.