Density Functional Theory Study On Adsorption Of C₁ Compound On Fe₂O₃ Surface And Catalytic Conversion Of CO₂ On Fe Modified In₂O₃ Surface On The Formation Of CO₂

With the acceleration of industrialization,massive CO2 emissions have led to global energy crisis and environmental change.In recent years,many scholars have been exploring the direction of CO2 capture and efficient utilization.Chemical chain combustion technology can greatly reduce the cost of CO2 source capture.The selection of oxygen carriers is crucial,and Fe2O3 is favored because of its low price and good thermochemical stability.The selection of catalyst plays an important role in the catalytic conversion of CO2.In2O3-based catalyst performs well in the hydrogenation of CO2 due to its high activity of CO2 conversion and high selectivity of methanol.In this paper,density functional theory(DFT)was used to study the adsorption of C1 compound on Fe2O3 surface and the catalytic conversion of CO2 on Femodified In2O3 surface,in order to provide some theoretical guidance for the formation of CO2 chemical chain combustion and its catalytic conversion.In the process of chemical chain combustion of coal or other fuels,understanding the interaction between various reaction molecules and oxygen carrier is the key problem to realize the enhancement of chemical chain combustion technology.In this process,C1 compounds(CO,CO2,CH4,HCHO,CH3OH),H2 molecules and H2O molecules are all important reactants or products in the process of chemical chain combustion.How eVer,until now,the adsorption mechanism of C1 compound on the surface of Fe-base oxygen carrier Fe2O3 has not been fully understood.In this paper,density functional theory is used to compare and analyze the adsorption behavior between different C1,H2,H2O molecules and α-Fe2O3(001)surface,and to r eVeal the mechanism and law of interaction between C1 molecules and α-Fe2O3(001)surface.The results show that CH4,H2 and CO2 are physical adsorption on α-Fe2O3(001)surface,while CO,HCHO,CH3OH and H2O are chemical adsorption on α-Fe2O3(001)surface.By calculating various adsorption configurations of C1 compound on α-Fe2O3(001)surface,the stable configuration of C1 compound on α-Fe2O3(001)surface was obtained.Bader charge calculation and differential charge calculation show that charge transfer from α-Fe2O3(001)surface to gas molecules.The calculation of state density shows that there is electron orbital hybridization between α-Fe2O3(001)surface and gas molecules after adsorption.Catalytic conversion after CO2 enrichment is of great significance for CO2 emission reduction and resource utilization.In2O3-based catalyst plays a key role in CO2 conversion and selectivity of methanol.How eVer,In2O3-based catalyst has a low CO2 conversion rate,which limits the methanol yield.The modification of In2O3 catalyst by doping metal is helpful to improve its activity in CO2 hydrosynthesis of methanol and increase the methanol yield.In this paper,the reaction path and mechanism of CO2 hydrogenation to methanol doped with Fe on In2O3(110)surface were studied.The results show that Fe doping promotes H2 dissociation and leads to oxygen vacancy on In2O3(110)surface.In addition,Fe atom also participated in the activation of CO2,which promoted the formation of HCOO.By studying the HCOO route of CO2 hydrogenation to methanol on Fe doped In2O3(110)surface,it was found that Fe doping on the surface of In2O3(110)can improve surface stability and catalytic activity.At the same time,the reaction energy of CO2 generation of methanol on Fe doped In2O3(110)surface is higher than that on In2O3(110)surface,indicating that Fe doped In2O3(110)surface is conducive to the stable adsorption of CO2 and the activation of hydrogenation to generate HCOO,which can effectively improve the yield of methanol.