Polarized Ni<sup>0</sup>-Ni<sup>δ+</sup> Catalysts Enable Asymmetric C–C Coupling for Long-Chain Hydrocarbons in Electrochemical CO<sub>2</sub> Reduction
Haowen Ding, Wenwei Cai, Xiaoling Yang, Yu Zhang, Shunning Li, Feng Pan, Shisheng Zheng
Abstract
The efficient electrochemical CO 2 reduction reaction (CO 2 RR) to long-chain hydrocarbons (C 3+ ) still remains a formidable task even on the widely investigated copper-based catalysts. Recently, nickel-based catalysts have garnered wide attention for their promising ability to generate C 3+ products. The design of Ni 0 -Ni δ+ domains, analogous to the renowned Cu 0 -Cu δ+ strategy, stands out as a hallmark approach, achieving substantial yields of C 3 –C 6 compounds. However, theoretical understanding remains significantly limited. Here, we employ full-solvent ab initio molecular dynamics simulations with a slow-growth approach to investigate Ni 0 -Ni δ+ -mediated C–C coupling at partially polarized nickel. In this system, the nonpolarized region is constantly covered by the generated *CO, while the polarized domain─through strategic modulation of Ni’s d-band center─mitigates the poisoning effects of *CO 2 and *CO, thereby enhancing their activation. This facilitates C–C coupling primarily between *COOH and *CH x (x = 1, 2), with significantly lower kinetic barriers compared to conventional *CO-involved pathways, laying the foundation for sustained carbon chain growth. Extending this concept to other metals ( M = Fe, Rh, Pd, Co and Ru) with similar adsorption characteristics akin to Ni further underscores the potential of M 0 -M δ+ domains for CO 2 electroreduction. Our study elucidates the microscopic mechanisms by which polarization strategies promote the formation of long-chain products, providing an original perspective for designing CO 2 electroreduction catalysts.