Study On Coupled Reduction Reaction Of Thermal Decomposition Of Carbonates For Co₂ Emission Reduction

Due to the social economy’s rapid growth,the demand for fossil fuels in industrial production has increased significantly,and the massive emission of excessive greenhouse gas CO₂has caused irreversible impact on the global ecological environment.How to reduce atmospheric CO₂content and transform it efficiently is an urgent problem to be solved.Based on the goal of CO₂reduction in the heavy emission industry,this paper took methane as a hydrogen donor molecule to explore the influence of methane molecules on the thermal decomposition of carbonates.Furthermore,to decrease reaction temperature and carbon deposition,O₂was introduced into reaction system.The influence of O₂was further explored by experiments.In addition,based on the advantages and characteristics of layered double hydroxides（LDHs）,single-atom alloy（SAA）catalysts with excellent performance in the light-driven dry reforming of methane（DRM）reaction were prepared.At the same time,based on the large amount of CO₂emission in the thermal decomposition reaction of carbonate,CO₂was converted by combining the CO₂-releasing thermal decomposition reaction of carbonate with the CO₂-consuming dry reforming of methane reaction The research contents and results are as follows:1、Traditional process industries such as cement,steel and resistant materials often involve the thermal decomposition of carbonates,in which large amounts of CO₂released.In this paper,the thermal decomposition of carbonates under methane atmosphere were conducted,in which syngas was obtained at 800°C.Furthermore,to decrease reaction temperature and carbon deposition,we conducted the thermal decomposition of carbonates under methane and O₂atmosphere.Experiments proved syngas was obtained at 500°C.Meanwhile,high-quality metal oxide was obtained.This text provided ideas and guidance for realizing energy saving and emission reduction in thermal decomposition of carbonate process in traditional industries.2、Considering the drawbacks of high temperature,poor catalytic activity and carbon deposition in dry reforming of methane,single-atom alloy（SAA）catalysts were constructed using LDHs as precursor.In the photothermal dry reforming of methane reaction,the production rates of H₂and CO reached 8.98 and 10.70 mmol·g^-1·min^-1,respectively.Furthermore,CO₂-releasing thermal decomposition of carbonates was coupled with the CO₂-consuming dry reforming of methane reaction to reduce CO₂emission.The selectivity of CO₂was reduced to about 25%and the maximum production rates of H₂and CO can reach 0.68 and 0.44 mmol·g^-1·min^-1,respectively.This work indicated an effective strategy to build highly reactive SAA catalysts for DRM applications and provided a sustainable method to utilize and convert surplus CO₂in actual production industries for the synthesis of value-added chemicals.