Study On The Advanced Biomass-Derived Porous Materials For Capture And Utilization Of Carbon Dioxide

The concentration of CO₂ in the atmosphere has increased dramatically since the industrial revolution,which has caused serious greenhouse effect and results severe environmental problems.Therefore,decreasing the concentration of CO₂ in the atmosphere has become a research hotspot of environment and global energy.Based on this issue,we proposed two solutions in this paper.One method is to adsorb and store CO₂ by adsorbents;the other way is to electrochemically reduce CO₂ by electrocatalysts to high energy density chemicals such as CO,HCOOH,CH₄,so as to relize the reuse of CO₂.Among the various adsorption and catalytic materials,porous materials stand out due to their intrinsic advantages,such as high specific surface area,good chemical and thermal stability,controllable pore channels and surface structure.Biomass materials are cheap,easy to obtain,widely available,and environmentally friendly,so the preparation of porous materials using biomass materials as precursors for adsorption and reduction of is a subject of high research value.The main research contents and results of this paper are as follows:（1）A series of porous carbon materials with high nitrogen content and high specific surface area were prepared from nitrogen-containing bio-waste of shrimp shells.The samples exhibit excellent CO₂ uptake capacities,at 273 K,298 K and1bar,the CO₂ uptake was up to 6.82 and 4.20 mmol g^-1,respectively.In addition,the samples have moderate CO₂ adsorption heat and good regeneration performance.The samples also have outstanding adsorption selectivity for binary mixture gas of CO₂/N₂（15/85,flue gas）and CO₂/CH₄（40/60,biogas）,which could effectively separate CO₂ from the two gas mixtures.These results indicate that the prepared porous carbon are appropriate CO₂ adsorbents and mixed gas separators.（2）Nitrogen-containing porous carbon was synthetized using nitrogen-containing biomass of chitosan as precursor,and non-noble copper was used as modifier to prepare the electrocatalyst for the carbon dioxide electrochemical reduction reaction.The obtained catalyst can efficiently reduce CO₂ to CO,and the faradic efficiency（FE）of CO is up to 90%at the overpotential of-0.7 V（vs.RHE）.What’s more,the catalyst can be used stably for more than 30 hours.