In this work, we report an ab initio investigation based on density functional theory calculations within van der Waals D3 corrections to investigate the adsorption properties and activation of CO2 on transition-metal (TM) 13-atom clusters (TM = Ru, Rh, Pd, Ag), which is a key step for the development of subnano catalysts for the conversion of CO2 to high-value products. From our analyses, which include calculations of several properties and the Spearman correlation analysis, we found that CO2 adopts two distinct structures on the selected TM13 clusters, namely, a bent CO2 configuration in which the OCO angle is about 125 to 150° (chemisorption), which is the lowest energy CO2/TM13 configuration for TM = Ru, Rh, Pd. As in the gas phase, the linear CO2 structure yields the lowest energy for CO2/Ag13 and several higher energy configurations for TM = Ru, Rh, Pd. The bent CO2 (activated) is driven by a chemisorption CO2-TM13 interaction due to the charge transfer from the TM13 clusters toward CO2, while a weak physisorption interaction is obtained for the linear CO2 on the TM13 clusters. Thus, the CO2 activation occurs only in the first case and it is driven by charge transfer from the TM13 clusters to the CO2 molecule (i.e., CO2-δ), which is confirmed by our Bader charge analysis and vibrational frequencies.

中文翻译：

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从头开始研究CO在13原子4d团簇上的吸附。

在这项工作中，我们报告了基于范德华D3校正内的密度泛函理论计算的从头算研究，以研究过渡金属（TM）13原子团簇（TM = Ru，Rh，Pd的吸附特性和CO2的活化）。 （Ag），这是开发亚纳米催化剂以将CO2转化为高价值产品的关键步骤。从我们的分析（包括几个属性的计算和Spearman相关分析）中，我们发现CO2在选定的TM13簇上采用两种截然不同的结构，即，弯曲的CO2构型，其中OCO角约为125至150°（化学吸附） ，这是TM = Ru，Rh，Pd时能量最低的CO2 / TM13配置。与气相一样 线性CO2结构产生的CO2 / Ag13能量最低，而TM = Ru，Rh，Pd的能量结构更高。由于电荷从TM13团簇向CO2转移，化学吸附CO2-TM13相互作用驱动了弯曲的CO2（活化），而对于TM13团簇上的线性CO2，则获得了较弱的物理吸附相互作用。因此，CO2活化仅在第一种情况下发生，并且受电荷从TM13团簇转移至CO2分子（即CO2-δ）的驱动，这已通过我们的Bader电荷分析和振动频率得到了证实。