CO2 chemisorption and dissociation on flat and stepped transition metal surfaces
CO2 chemisorption and dissociation on flat and stepped transition metal surfaces
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DOI：
10.1016/j.apsusc.2022.154024
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发表时间：
2022-06-28
影响因子：
6.7
通讯作者：
Guo, Hua
中科院分区：
文献类型：
--
作者：
Jin, Wei;Wang, Yingqi;Guo, Hua
作为一种有前景且实用的减少二氧化碳排放的方法，将二氧化碳转化为增值化学品最近受到了极大关注。二氧化碳在催化剂表面的活化可能通过具有弯曲二氧化碳构型的化学吸附态进行，在此过程中，底物电子转移到二氧化碳吸附质的反键轨道中。基于密度泛函理论计算，我们对几种过渡金属的平面和台阶表面上的二氧化碳化学吸附和解离进行了广泛研究。化学吸附的二氧化碳的结合能与从金属到二氧化碳的电子转移程度密切相关，二氧化碳吸附能与其巴德电荷之间的线性关系证明了这一点。在平面和台阶表面上化学吸附的二氧化碳解离过程中，发现过渡态结合能与初始态或最终态结合能之间存在过渡态标度（TSS）相关性，这可用于预测催化剂的效率。我们的结果表明，台阶表面的缺陷位点对二氧化碳的化学活化和解离有很大影响。
As a promising and practical way to decrease CO2 emissions, the conversion of CO2 to value-added chemicals has received significant recent attention. The activation of CO2 on catalyst surfaces might proceed via a chemi-sorption state with a bent CO2 configuration, in which substrate electrons are transferred into the antibonding orbital of the CO2 adsorbate. Based on density functional theory calculations, we present an extensive survey of CO2 chemisorption and dissociation on flat and stepped surfaces of several transition metals. The binding energy of chemisorbed CO2 is closely correlated with the extent of electron transfer from the metal to CO2, as evidenced by a linear relationship found between the CO2 adsorption energy and its Bader charge. Transition state scaling (TSS) correlations between binding energies of transition states and binding energies of either initial or final states are found to exist for the dissociation of the chemisorbed CO2 on flat and stepped surfaces, which can be used to predict the efficacies of the catalysts. Our results show that defect sites at stepped surfaces have a strong influence on CO2 chemical activation and dissociation.