Density Functional Theory Study on the Mechanism of Calcium Sulfate Reductive Decomposition by Carbon Monoxide
Density Functional Theory Study on the Mechanism of Calcium Sulfate Reductive Decomposition by Carbon Monoxide
复制标题
DOI：
10.1021/ie202203b
复制
发表时间：
2012-04
影响因子：
4.2
通讯作者：
Xuemei Zhang;Xingfu Song;Ze Sun;Ping Li;Jianguo Yu
中科院分区：
文献类型：
--
作者：
Xuemei Zhang;Xingfu Song;Ze Sun;Ping Li;Jianguo Yu
硫酸钙（CaSO 4）还原分解为硫化钙（CaS）是硬石膏资源化利用的重要方法之一。当CaSO_4被一氧化碳（CO）还原分解时，取决于反应温度和反应物浓度，CaSO_4的分解产物中通常含有CaS和/或氧化钙（CaO）。本文在密度泛函理论（DFT）的框架下研究了CO还原CaSO 4的反应机理。在计算中，交换相关项近似Perdew-Wang（PW 91），广义梯度近似（GGA）家族中的泛函。为了研究CO与CaSO 4的相互作用，分析了CaSO 4分解的过渡态和最小能量路径。结果表明，当CO与CaSO 4的化学计量比为4：1时，可以用CO还原CaSO 4得到CaS产物，CaSO 4分解为CaSO 3是反应的速率控制步骤，而CaSO 3的分解速率随CO浓度的增加而增加。
The reductive decomposition of calcium sulfate (CaSO4) to calcium sulfide (CaS) was one of the most important methods for anhydrite resource utilization. When CaSO4 was decomposed reductively by carbon monoxide (CO), usually there were CaS and/or calcium oxide (CaO) in the decomposition products of CaSO4 depending on the reaction temperature and reactant concentrations. In this paper, the mechanism of CaSO4 reductive decomposition by CO was studied in the framework of density functional theory (DFT). In the calculation, the exchange-correlation term was approximated by Perdew–Wang (PW91), a functional within the generalized gradient approximation (GGA) family. To study the interaction of CO and CaSO4, the transition states of CaSO4 decomposition and the minimum energy path (MEP) were analyzed. The results showed that the CaS product could be obtained when CaSO4 was reduced by CO with the 4:1 stoichiometric ratio of CO and CaSO4, and the decomposition of CaSO4 to CaSO3 was the rate-determining step, and ac...