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arXiv · 2608.27850

Mode-Specific Dynamics of $\text{CO}_2$ Hydrogenation on Copper: The Hidden Role of Molecular Rotation

Junfan Xia·Zhikai Jiang·Yaolong Zhang·Bo Peng·Hua Guo·Bin Jiang
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Abstract

Catalytic hydrogenation of $\text{CO}_2$ to formate on copper is a key elementary step for $\text{CO}_2$ utilization. Previous experimental and theoretical studies suggested an Eley-Rideal mechanism for this reaction, promoted by bending vibrational excitation, yet direct state resolved evidence remains lacking. Here, we present first-principles dynamical predictions for $\text{CO}_2$ hydrogenation on Cu(111) based on an accurate full-dimensional neural network potential energy surface. Our calculations near-quantitatively reproduce the measured reaction probabilities, including their nozzle-temperature and incidence-energy dependence. Our state-resolved results indicate that while vibrational excitation of the bending mode enhances reactivity, it alone cannot account for the observed reactivity increase with nozzle temperature. Instead, rotational excitation plays a dominant role, mainly attributable to the significant change in anisotropy of the molecular polar orientation as $\text{CO}_2$ accesses the transition state. This mode-specific insight reinforces the hidden role of rotation in surface reactivity, opening new avenues for state-selective control of $\text{CO}_2$ hydrogenation on heterogenous catalysts.

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Junfan Xia, Zhikai Jiang, Yaolong Zhang, Bo Peng, Hua Guo, Bin Jiang. 2026-08-31. Mode-Specific Dynamics of $\text{CO}_2$ Hydrogenation on Copper: The Hidden Role of Molecular Rotation. https://arxiv.org/abs/2608.27850

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