CaO基CO_2吸附剂掺杂/负载活性组分的第一性原理  

Promoted CaO-Based CO_2 Sorbents by First-Principles Calculations

作　　者：刘亮[1,2] 洪迪昆 冯于川 郭欣 

机构地区：[1]华中科技大学煤燃烧国家重点实验室,武汉430074 [2]华中科技大学能源与动力工程学院,武汉430074

出　　处：《燃烧科学与技术》2017年第5期412-417,共6页Journal of Combustion Science and Technology

基　　金：国家自然科学基金资助项目(51576085)

摘　　要：采用第一性原理方法研究了NH_3在CaO(100)洁净表面以及在该表面负载9种碱金属及碱土金属活性组分后的吸附情况.结果表明CaO(100)表面的氧顶位为最稳定的NH_3吸附位点,并通过NH_3中的C与CaO中的O成键形成CO_3^(2-).CaO(100)表面负载活性组分后,其表面结构发生了变化,表面与活性组分之间发生了电荷转移,从而使得负载活性组分的CaO表面对NH_3的吸附作用均有所增强.其中,Na、K、Rb、Cs由于具有较强的电正性,对氧化钙表面NH_3吸附的促进作用较为强烈,因而在实际的应用中通过负载电正性较强的活性组分可能会对CaO的碳酸化性能有所增强.First-principles calculations were conducted to study the adsorption of NH3 on the CaO（100） perfect surface and promoted surfaces by alkali and alkaline-earth metals.The results show that NH3 tends to be adsorbed onO-top site to form the most stable configuration and the carbonate-like CO3^2- is formed through the bondage of atom C in NH3 and atomO in CaO.For each promoted surface,electron transfer proceeded between surface and promoters,which can enhance the interaction between NH3 and the surface.Based on the adsorption ability of NH3 on the promoted CaO surface,Na,K,Rb and Cs were identified as adequate promoters among the nine metals due to their high electro-positivity.In the actual application of CaO based sorbents for NH3 capture,the carbonation performance of sorbents could be enhanced by doping promoters with high electro-positivity.

关 键 词：CAO 密度泛函理论 碳酸化 CO2捕集 

分 类 号：TK448.21[动力工程及工程热物理—动力机械及工程]