ChemPhysChem, e20220053, 1-8 (2023)

Weak Interactions Initiate C-H and C-C Bond Dissociation of Ethane on Nb_n⁺ Clusters

Wen Gan^a,b Benben Huang^a,b, Chaonan Cui^a,b, Klavs Hansen^c, and Zhixun Luo^*,a,b

1. Beijing National Laboratory for Molecular Science, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China

2. University of Chinese Academy of Sciences, Beijing 100049, China

3. Center for Joint Quantum Studies and Department of Physics, School of Science, Tianjin University, 92 Weijin Road, Tianjin 300072, China

*  zxluo@iccas.ac.cn

Abstract

The conversion of ethane into value-added chemicals under ambient conditions has attracted much attention but the mechanisms remain not fully understood. Here we report a study on the reaction of ethane with thermalized Nb_n⁺ clusters based on a multiple-ion laminar flow tube reactor combined with a triple quadrupole mass spectrometer (MIFT-TQMS). It is found that ethane reacts with Nb_n⁺ clusters to form both products of dehydrogenation and methane-removal (odd-carbon products). Combined with density functional theory (DFT) calculations, we studied the reaction mechanisms of the C−C bond activation and C−H bond cleavage on the Nb_n⁺ clusters. It is unveiled that hydrogen atom transfer (HAT) initiates the reaction process, giving rise to the formation of Nb−C bonds and an elongated C−C distance in the HNb_n⁺CH₂CH₃ motif. Subsequent reactions allow for C−C bond activation and a competitive HAT process which is associated with CH₄ removal or H₂ release, resulting in the production of the observed carbides.