The Adsorption Characteristics Of Carbon Dioxide And Vapor On The Surface Of Titanium Dioxide-based Materials

With the development of society,the problems of energy and environment have become more and more important.The massive burning of fossil fuels has caused a sharp increase in atmospheric carbon dioxide concentration,leading to global warming.In this context,countries all over the world have put forward the vision of carbon neutrality,and one of the important means to achieve this goal is carbon dioxide conversion and utilization technology.Due to the superior energy utilization and good material circulation,the technology of reducing carbon dioxide through water using solar energy has attracted wide attention.The co-adsorption of carbon dioxide and water is an important part of the conversion process,which is of great significance to catalyst design and reaction control.Titanium dioxide is widely used in solar carbon dioxide conversion due to its chemical stability,non-toxicity and low cost advantages.Therefore,this article will focus on the adsorption characteristics of carbon dioxide and water on the surface of titanium dioxide materials.In addition,by loading titanium dioxide with different metal oxides,the surface adsorption characteristics of the material before and after the modification are studied,and the regulation effect of metal oxides is analyzed.Studies have shown that the introduction of water will reduce the adsorption strength of carbon dioxide on the surface of Ti O₂.The GCMC simulation shows that under the simulated conditions,the adsorption capacity of carbon dioxide will decrease due to the competitive adsorption of water.In-situ infrared spectroscopy experiments with gradual heating indicate that in the co-adsorption system,the bidentate carbonate formed by surface adsorption is unstable at high temperatures,and within the studied temperature range,the increase in temperature leads to a higher degree of carbon dioxide activation,which is benefit to the formation of bicarbonate;Compared with Ti O2,the modified material prepared by the co-precipitation method exhibits different carbon dioxide and water adsorption performance.Among them,Mg O/Ti O₂ shows strong carbon dioxide adsorption capacity and strong water adsorption capacity,Zn O/Ti O₂ shows weak adsorption capacity for water,and Al₂O₃/Ti O₂ shows weak adsorption capacity for hydroxyl groups;Through the comparative analysis of CO₂-TPD and DFT theoretical calculation,it is found that the supported metal oxide material changes the relative number of surface basic sites and the adsorption energy of carbon dioxide and water,and promotes the interaction between hydroxyl and carbon dioxide.Therefore,the use of loads of different metal oxides can achieve the regulation of water and carbon dioxide adsorption to a certain extent.