Ni Cluster‐Decorated Single‐Atom Catalysts Achieve Near‐Unity CO2‐to‐CO Conversion with an Ultrawide Potential Window of ≈1.7 V

• Published in: Small (Weinheim an der Bergstrasse, Germany) Germany), 2024-12, Vol.20 (49), p.e2405367-n/a
• Main Authors: Li, Yaqian, Cao, Xi, Chen, Qingqing, Pan, Rongrong, Zhang, Jian, Meng, Ge, Yang, Yun, Li, Yapeng, Mao, Junjie, Chen, Wei
• Format: Article
• Language: English
• Subjects: Carbon dioxide; Carbon monoxide; Catalysis; Catalysts; Chemical reduction; CO2‐to‐CO conversion; Coordination polymers; Density functional theory; Electrocatalysts; H2O dissociation; hydrogen spillover; In situ measurement; Nanoclusters; Ni nanocluster; Ni single atom; Nitrogen; Protonation; Protons; Zinc coordination
• ISSN: 1613-6810; 1613-6829; 1613-6829
• DOI: 10.1002/smll.202405367

Developing efficient electrocatalysts for CO2 reduction to CO within a broad potential range is meaningful for cascade application integration. In this work, hydrogen spillover is created and utilized to cultivate a proton‐rich environment via the simple thermolysis of a Ni‐doped Zn coordination polymer (Zn CPs (Ni)) to create asymmetric Ni single atoms co‐located with adjacent Ni nanoclusters on nitrogen‐doped carbon, termed as NiNC&SA/N‐C, which expedites the hydrogenation of adsorbed CO2. Therefore, the sample demonstrates near‐unity CO2‐to‐CO conversion efficiency under pH‐universal conditions in ultra‐wide potential windows: −0.39 to −2.05 V versus RHE with the current densities ranging from 0.1 to 1.0 A cm−2 in alkaline conditions, −0.83 to −2.40 V versus RHE from 0.1 to 0.9 A cm−2 in neutral environments, and −0.98 to −2.25 V versus RHE across 0.1 to 0.8 A cm−2 in acid conditions. Corresponding in situ measurements and density functional theory (DFT) calculations suggest that the enhanced H2O dissociation and more efficient hydrogen spillover on NiNC&SA/N‐C (compared to NiSA/N‐C) accelerate the protonation of adsorbed CO2 to form *COOH intermediates. This work emphasizes the significant role of proton spillover in CO2RR, opening novel avenues for designing high‐performance catalysts applicable to various electrocatalytic processes. Adjacent Nickel (Ni) nanoclusters can induce the adsorption of CO2 and steer the rapid protonation of adsorbed CO2 on the Ni single atoms sites to form *COOH intermediate on NiNC&SA/N‐C via the positive role of hydrogen spillover, making this material exhibit a near‐unity CO2‐to‐CO conversion, exceeding 95%, at industrial‐level current densities (JCO) ranging from 0.1 to 1.0 A cm−2, with an extensive potential window of ≈1.7 V, ranging from −0.39 to −2.05 V.