Ligand-engineered octanuclear bismuth-oxo clusters with exposed active sites for enhanced CO2-to-HCOOH electroreduction
Hao-Nan Zhou , Lan-Yan Li , Hong-Bing Mo , Yi-Xin Li , Jun Yan , Chao Liu
Electrochemical CO2 reduction (eCO2RR) has emerged as a promising carbon-neutral strategy that synergistically integrates renewable energy conversion with environmental remediation [1-3]. This technology's dual capability of mitigating greenhouse gas emissions while producing value-added chemicals positions it at the forefront of sustainable energy research [4-19]. Among various reduction products, formic acid (HCOOH) presents distinctive advantages as an ideal energy carrier, including high volumetric hydrogen storage capacity, compatibility with direct formic acid fuel cells, and superior transport stability compared to gaseous alternatives [20-22]. These merits have driven intensive research efforts toward developing high-performance electrocatalysts for selective CO2-to-HCOOH conversion [23-30].
Bismuth-based catalysts have garnered particular attention due to their inherent selectivity toward HCOOH production, with recent advances highlighting the potential of bismuth-oxo clusters as molecularly precise analogs of bismuth oxide nanomaterials [26]. These well-defined clusters offer unique opportunities to establish structure-activity relationships through their atomically precise metal cores and tunable ligand environments. However, a critical challenge persists: most reported bismuth-oxo clusters exhibit limited electrochemical stability under operational conditions, particularly in neutral/alkaline electrolytes, due to ligand dissociation and structural reorganization [31-33].
Current stabilization strategies focus on macrocyclic ligand encapsulation, where rigid organic frameworks (e.g., calix[n]arenes, thiacalix[4]arenes) form protective shells around cluster cores [34-38]. While this approach enhances structural integrity of the nanoclusters, practical implementation faces two key limitations: (1) Geometric mismatch between rigid macrocycles and cluster surfaces often creates unprotected interfacial regions, and (2) complete encapsulation tends to bury catalytically active sites, compromising their accessibility [39-47]. Recent attempts to address these issues through auxiliary ligand filling have achieved partial success, but introduce new trade-offs-excessive ligand loading may either obscure active sites or induce steric strain that destabilizes the cluster architecture [48,49].
To resolve these conflicting requirements, we propose a ligand engineering strategy that achieves both structural stabilization and catalytic site optimization. Through rational design of hybrid ligand systems combining macrocyclic TC4A with modulatory co-ligands, we developed two novel octanuclear bismuth-oxo clusters (Bi8-DMF and Bi8-Fc) with tailored surface architectures. The Bi8-DMF variant features strategically exposed bismuth sites coordinated by labile solvent molecules, while Bi8-Fc demonstrates complete ligand encapsulation through ferrocene carboxylate integration. Systematic electrochemical evaluation reveals that controlled ligand coverage rather than maximal protection dictates catalytic performance. Catalytic tests revealed that the Bi8-DMF cluster, protected by TC4A alone, efficiently catalyzes the electroreduction of CO2 to formic acid, exhibiting a Faradaic efficiency (FE) for HCOOH of over 90% across a broad potential window from −0.8 V to −1.6 V, with excellent durability for over 24 h. This performance significantly outperforms that of the Bi8-Fc, which, despite being protected by dual ligands, achieves a maximum FE of only 60% for formic acid at a specific potential. Density functional theory (DFT) calculations suggest that the surface-exposed bismuth sites in the Bi8-DMF cluster are more effective at stabilizing the *OCHO intermediate, thereby facilitating the reduction of CO2 to formic acid.
The Bi8-DMF cluster was synthesized through a one-step solvothermal approach. The reaction system comprised Bi(NO3)3, TC4A, and 2, 4-dihydroxybenzoic acid in a mixed CH3OH/DMF solvent (4 mL total, v/v = 2:2), followed by thermal treatment at 80 ℃ for three days. Single-crystal X-ray diffraction (SCXRD) analysis revealed the molecular formula {H4Bi8O4(TC4A)5(DMF)3}·2DMF (Figs. 1A and B), crystallizing in the trigonal system with space group P-1. The asymmetric unit contains eight distinct Bi atoms, two μ4O atoms, two μ3O atoms, five TC4A ligands, and three coordinated DMF molecules, forming an elongated rod-like architecture. The molecular structure features two distinct subunits: (1) A sandwich-type {Bi3O2@(TC4A)2} subunit (Fig. 1C), where three Bi atoms form a triangular plane bridged by a μ3O atom, asymmetrically encapsulated between two TC4A ligands; (2) A {Bi5O2@(TC4A)₃} subunit (Fig. 1D) containing five Bi atoms interconnected through both μ3O and μ4O bridges, creating a Bi5O2 core stabilized by three triangularly arranged TC4A ligands. These subunits are interconnected via an additional μ4O bridge to form the final {Bi8O4@(TC4A)5} framework. As illustrated in Fig. 1E, the Bi centers exhibit diverse coordination geometries categorized into five groups with coordination numbers ranging from 4 to 7. Notably, the terminal Bi atoms coordinate with one and two labile DMF molecules, respectively. Given the dynamic nature of these solvent interactions, these sites are proposed as potential catalytic centers for subsequent reactivity studies.
Structural analysis reveals the Bi8-DMF cluster can be conceptually divided into two fundamental building units: {Bi3O2@(TC4A)2} and {Bi5O2@(TC4A)3}. Intriguingly, this structural division was corroborated through electrospray ionization mass spectrometry (ESI-MS) analysis. Positive-mode ESI-MS of Bi8-DMF crystals dissolved in CH2Cl2 (Fig. 2) displayed characteristic fragmentation patterns. The spectrum prominently featured a + 2 charged species at m/z = 2643.98 (1a), corresponding to the intact {Bi8O2(TC4A)5}2+ cluster (calcd. m/z = 2643.94). A weaker +1 ion at m/z = 5304.79 (1b) matched the protonated {HBi8O3(TC4A)5}1+ species (calcd. m/z = 5304.89). Crucially, two intense signals corresponding to the proposed subunits were observed: {Bi5O2(TC4A)3}1+ at m/z = 3227.72 (1c, calcd. 3227.53) and {HBi3O(TC4A)2}1+ at m/z = 2076.34 (1d, calcd. 2076.36). This provides direct experimental evidence for the dual module assembly mechanism.
Notably, an additional +1 peak at m/z = 2318.36 suggested the formation of a {Bi4O@(TC4A)2}1+ intermediate, likely generated through structural rearrangement of the {Bi3O(TC4A)2} unit. This hypothesis was experimentally validated through ligand substitution experiments. Recrystallization of Bi8-DMF in DMF/CH₃OH with excess bromosalicylic acid (SalH2) yielded Bi4-Sal crystals (∞¹{Bi4O(TC4A)2(Sal)}), forming a one-dimensional polymeric structure (Fig. 3A). Four Bi sites are bridged by a μ4O atom, forming a quadrilateral arrangement (Fig. 3B), and are situated between two TC4A ligands, creating a sandwich-type {Bi4O(TC4A)2} unit. This Bi4 unit is further bridged by bromosalicylic acid ligands, forming a one-dimensional infinite polymeric structure.
Mass spectrometry analysis combined with structural evolution studies reveal critical stability differences between the two clusters. The Bi8-DMF assembly, constructed exclusively with TC4A ligands, exhibits limited solution stability and undergoes structural dissociation, as evidenced by its transformation into the Bi4-Sal derivative. This inherent instability can be effectively mitigated through strategic incorporation of auxiliary ligands - a principle demonstrated in the synthesis of Bi8-Fc. While maintaining similar synthetic protocols to Bi8-DMF, the Bi8-Fc system introduces ferrocene carboxylate co-ligands, yielding the hybrid architecture {H4Bi8O4(TC4A)4(FcCOO)2} (Figs. 4A and B). Crystallographic analysis delineates a Bi8O4 core comprising eight Bi3+ ions interconnected through two μ4O and two μ3O bridges (Fig. 4C). This metallo-oxo framework is enveloped by four TC4A ligands exhibiting distinct coordination patterns: two fully deprotonated TC4A units adopt the μ4-κ(O)2: κ(O)2: κ(O)2: κ(O)2 binding mode analogous to {Bi4@TC4A}, while the remaining two TC4A ligands coordinate via a μ3-κ(O)1: κ(O)2: κ(O)1 configuration with one non-coordinating oxygen per ligand. The structural integrity is further enhanced by two ferrocene carboxylate ligands positioned at apical sites, each employing μ4-bridging modes through their carboxyl groups to anchor four bismuth centers simultaneously (Fig. 4D). This dual-ligand strategy achieves complete encapsulation of the Bi8O4 core within a hybrid organic shell. Notably, Bi8-Fc represents the first documented bismuth-oxo cluster incorporating metallocene-based ligands, establishing a new paradigm in polynuclear bismuth complex design.
We further examined the behavior of the Bi8-Fc cluster in solution using ESI-MS (Fig. 5). The spectrum revealed four distinct peaks corresponding to ligand dissociation processes: (1) A prominent +2 charged peak at m/z = 5149.56 aligns with the theoretical m/z = 5149.64 for [H2Bi8O4(TC4A)4(FcCOO)2]2+, confirming the intact cluster structure; (2) The +1 charged species at m/z = 4702.63 (observed; calcd. 4702.74) corresponds to [H4NaBi8O4(TC4A)4(DMF)]⁺, indicating partial loss of two FcCOO⁻ ligands; (3) A neutral cluster at m/z = 4464.29 (observed; calcd. 4464.65) assigned to [H2Bi8O4(TC4A)3(FcCOO)2(MeOH)] demonstrates removal of one TC4A ligand with methanol coordination; (4) The species at m/z = 4277.32 (observed; calcd. 4277.67), identified as [Na2Bi8O4(TC4A)3(FcCOO)(DMF)], reveals simultaneous loss of one TC4A and one FcCOO⁻ ligand. These sequential ligand dissociation events contrast sharply with the complete core rearrangement observed in Bi8-DMF, suggesting that Bi8-Fc maintains its central Bi8O4 framework while undergoing controlled ligand shedding. This partial ligand loss with core preservation highlights the enhanced stability imparted by dual-ligand coordination in Bi8-Fc compared to the single-ligand-protected Bi8-DMF system.
The distinct ligand architectures of Bi8-Fc and Bi8-DMF clusters create fundamentally different catalytic microenvironments. Bi8-Fc features a densely packed ligand shell comprising TC4A and ferrocene carboxylic ligands, whereas Bi8-DMF replaces ferrocene derivatives with additional TC4A moieties and surface-bound DMF molecules, resulting in exposed Bi active sites. To systematically evaluate how these structural variations influence catalytic behavior, we investigated their performance in the electrochemical CO2 reduction reaction (eCO2RR) using a three-electrode H-cell configuration.
The electrocatalytic performance of two Bi8 clusters was systematically investigated using a dual-chamber gas-tight H-type electrochemical cell. Initial characterization through linear sweep voltammetry (LSV) in 0.5 mol/L KHCO₃ revealed distinct current-voltage responses under CO2-saturated versus N2-saturated conditions (Fig. 6A). Both catalysts demonstrated enhanced current densities and significantly shifted onset potentials (−0.7 V vs. RHE) in CO2-rich environments, establishing their preferential selectivity for CO2RR over the competing H2 evolution reaction (HER). Remarkably, under CO2 saturation, the current density surged to 38.0 and 36.0 mA/cm2 at −1.6 V vs. RHE for the respective clusters, underscoring their exceptional catalytic activity. Product analysis through gas chromatography (GC) and ion chromatography (IC) following 2-h electrolysis (−0.9~−1.6 V vs. RHE) identified formate as the dominant product, with trace amounts of H2 and CO as secondary products. Control experiments under N2 saturation crucially confirmed the exclusive origin of carbon-containing products from CO2 reduction, as no such products were detected in the absence of CO2. Additional blank tests without catalysts yielded only H2 evolution, further validating the intrinsic catalytic function of the Bi8 clusters.
Under CO2-saturated conditions, Bi8-DMF demonstrated exceptional Faradaic efficiency (FE) for formate production, maintaining values above 90% across a broad potential window from −0.9 V to −1.6 V vs. RHE. Notably, it achieved a peak FE of 92.79% at −1.0 V (Fig. 6B). In stark contrast, Bi8-Fc exhibited substantial competitive hydrogen evolution, with formate FE fluctuating between 50%−68% and concomitant H2 FE ranging from 29% to 40% in the same potential range (Fig. 6C). This pronounced disparity highlights Bi8-DMF's superior catalytic selectivity for CO2-to-formate conversion (Fig. 6D). The enhanced performance of Bi8-DMF was further corroborated by partial current density analysis (Fig. 6E). At −1.6 V, Bi8-DMF delivered a formate partial current density (jHCOOH) of 32.67 mA/cm2, representing a 1.54-fold enhancement over Bi8-Fc (21.22 mA/cm2) (Fig. 6F). Comparative turnover frequency (TOF) calculations across all tested potentials consistently revealed the superior intrinsic activity of Bi8-DMF (Fig. S25 in Supporting information), attributable to its optimized structural architecture and efficient bismuth site utilization.
Electrocatalytic stability assessment through chronoamperometric testing at −1.0 V revealed robust performance: current density remained stable above 20 mA/cm2 with sustained formate FE > 90% during the initial 20-h operation. Post-20 h, while FE retention persisted, current density attenuation suggested potential structural degradation. Post-catalysis characterization provided critical insights: MALDI-TOF-MS of recovered Bi8-DMF showed a dominant +1 charged species at m/z = 5304.79 (Fig. S36 in Supporting information), corresponding to {HBi8O3(TC4A)5}1+ (theoretical m/z = 5304.89). XPS analysis confirmed preservation of Bi3+ oxidation states after prolonged operation, indicating chemical stability under reaction conditions (Fig. S34 in Supporting information).
The eCO2RR mechanism mediated by Bi-based materials unfolds through consecutive stages initiated by chemisorption of CO2 onto catalytic active sites, followed by proton-coupled electron transfer (PCET) processes that generate key intermediates. The reaction pathway progresses through sequential transformations, beginning with the formation of *OCHO intermediates through initial PCET activation, followed by their conversion into adsorbed HCOOH species via subsequent proton-electron transfer steps, and ultimately culminating in the desorption of final products from the catalyst surface. To unravel this reaction network, we conducted in situ electrochemical attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR) measurements across a potential window from −0.9 V to −1.6 V vs. RHE (Fig. 7). When employing Bi8-DMF as the electrocatalyst, many characteristic spectral regions revealed voltage-dependent evolution of critical intermediates. As illustrated in Fig. 8, the peaks appear at 1326, 1471 and 1540 cm−1 attributed to the stretching vibration of m-CO32−, and at 1265, 1290 and 1560 cm−1 belonging to the stretching vibration of b-CO32− [44]. The bands at 1407 and 1654 cm−1 in the spectra are attributed to HCO3− [34]. Most importantly, the *OCHO intermediate signals detected at 1388 and 1588 cm−1 are generally regarded as key intermediates in the electrochemical CO2/HCOOH conversion and increase gradually with the applied potentials varying between −0.9 V and −1.6 V. Besides, the characteristic peaks of HCOO− (1617, 1685, 1716, 1735, 1735, and 1772 cm−1) start to appear with increasing voltage.
The reaction energy pathways for electrochemical CO2 reduction to HCOOH and CO, along with the competing HER, were systematically investigated through density functional theory (DFT) calculations. Fig. 8A presents the optimized configurations and corresponding energy profiles of key intermediates along the CO2 reduction reaction (CO2RR) pathways. To enhance computational efficiency while maintaining structural fidelity, the theoretical models were simplified by substituting tert‑butyl groups on the TC4A ligand with H atoms, thereby preserving the essential coordination environment of the Bi8-DMF cluster observed in experimental crystal structures. The proposed catalytic mechanisms reveal distinct reaction pathways: The CO production pathway follows the sequence CO2(g) → *COOH → *CO → CO(g), whereas formate generation proceeds through CO2(g) → *OCHO → *HCOOH → formate(l). As shown in Fig. 8B, the potential-determining step (PDS) for formate formation in Bi8-DMF corresponds to the desorption of *HCOOH intermediate, exhibiting a Gibbs free energy change (ΔG) of 0.91 eV. In contrast, the CO pathway demonstrates a significantly higher energy barrier at the initial proton-coupled electron transfer step (*CO2 + H⁺ + e⁻ → *COOH), with a ΔG value of 1.34 eV. Furthermore, calculated hydrogen adsorption energies (*H) revealed an unfavorable ΔG of 1.69 eV, thermodynamically disfavoring HER. This energy landscape analysis provides a fundamental rationale for the experimentally observed product selectivity, where Bi8-DMF exhibits superior Faradaic efficiency for HCOOH production compared to CO generation or H2 evolution. For the Bi8-Fc catalyst, the complete encapsulation of its bismuth-oxo cluster core by organic ligands results in the shielding of catalytic active sites and insufficient surface exposure. DFT computational analysis reveals that this structural constraint prevents the stable binding of key adsorbed intermediates (e.g., *OCHO or *COOH) to the cluster surface, indicating the inability of bismuth active sites to effectively stabilize these reaction intermediates. This mechanistic insight fundamentally explains the significantly lower CO2 reduction catalytic activity of the Bi8-Fc system compared to Bi8-DMF at the atomic scale.
In this work, we have demonstrated the critical role of ligand engineering in modulating the catalytic performance of polynuclear bismuth-oxo clusters for selective electrochemical CO2-to-formate conversion. Two structurally distinct octanuclear clusters, Bi8-DMF and Bi8-Fc, were synthesized via tailored ligand coordination strategies. The Bi8-DMF cluster, stabilized solely by TC4A ligands with surface-exposed Bi sites coordinated by labile DMF molecules, exhibits exceptional catalytic activity and selectivity, achieving > 90% FE for formate across a broad potential window with stable operation exceeding 20 h. In contrast, the Bi8-Fc analogue, featuring a fully encapsulated Bi-O core via dual-ligand coordination (TC4A and ferrocene carboxylate), shows inferior performance (60% maximum FEHCOOH) due to restricted active site accessibility. DFT calculations reveal that the exposed Bi sites in Bi8-DMF effectively stabilize the critical *OCHO intermediate through optimized orbital interactions, thereby lowering the energy barrier for CO2-to-formate conversion. This study establishes a clear structure-activity relationship in polynuclear bismuth catalysts, emphasizing that controlled ligand coverage—rather than maximal encapsulation—is essential for balancing stability and catalytic efficiency. The findings provide a molecular-level blueprint for designing next-generation CO2RR catalysts, highlighting the importance of strategically exposed metal sites and dynamic ligand environments in achieving high-performance electrochemical systems.
Hao-Nan Zhou: Writing – original draft, Investigation, Formal analysis, Data curation. Lan-Yan Li: Theoretical calculations. Hong-Bing Mo: Supervision, Funding acquisition. Yi-Xin Li: Funding acquisition. Jun Yan: Supervision. Chao Liu: Writing – review & editing, Supervision, Project administration, Funding acquisition.
The authors declare no competing financial interest.
This work was supported by the Natural Science Foundation of Hunan Province (No. 2023JJ30650) and the Central South University Innovation-Driven Research Programme (No. 2023CXQD061).
Supplementary material associated with this article can be found, in the online version, at doi:
Q. Tang, Q. Hao, Q. Zhu, et al., Adv. Energy Mater. 15 (2024) 403778.
L.L. Zhuo, P. Chen, K. Zheng, et al., Angew. Chem., Int. Ed. 61 (2022) e202204967. doi: 10.1002/anie.202204967
S. Navarro-Jaen, M. Virginie, J. Bonin, et al., Nat. Rev. Chem. 5 (2021) 564–579. doi: 10.1038/s41570-021-00289-y
F. Chen, Z.C. Yao, Z.H. Lyu, et al., eScience 4 (2024) 100172. doi: 10.1016/j.esci.2023.100172
T. Ma, Z. Jiao, H. Qiu, et al., eScience 4 (2024) 100246. doi: 10.1016/j.esci.2024.100246
H.H. Wong, M. Sun, T. Wu, et al., eScience 4 (2024) 100140. doi: 10.1016/j.esci.2023.100140
S. Yoo, S. Yoo, G. Deng, et al., Adv. Mater. 36 (2024) e2313032. doi: 10.1002/adma.202313032
X. Zhu, Y. Xu, L. Ran, et al., Small Struct. (2024) 2400548.
K. Li, S. Zou, J. Zhang, et al., ACS Catal. 13 (2023) 9346–9351. doi: 10.1021/acscatal.3c01444
W.L. Mu, L. Li, X.Z. Cong, et al., J. Am. Chem. Soc. 146 (2024) 28131–28140.
L. Tang, Y. Luo, X. Ma, et al., Angew. Chem. Int. Ed. 62 (2023) e202300553. doi: 10.1002/anie.202300553
G. Deng, H. Yun, M.S. Bootharaju, et al., J. Am. Chem. Soc. 145 (2023) 27407–27414. doi: 10.1021/jacs.3c08438
J. Xu, L. Xiong, X. Cai, et al., Chem. Sci. 13 (2022) 2778–2782. doi: 10.1039/d1sc07178e
S. Zhuang, D. Chen, L. Liao, et al., Angew. Chem. Int. Ed. 59 (2020) 3073–3077. doi: 10.1002/anie.201912845
G. Deng, J. Kim, M.S. Bootharaju, et al., J. Am. Chem. Soc. 145 (2023) 3401–3407. doi: 10.1021/jacs.2c10338
B.L. Han, L.C. Zhao, Z.R. Yuan, et al., Adv. Funct. Mater. 35 (2025) 2500149. doi: 10.1002/adfm.202500149
N.H. Huang, J.L. Hou, Y. Wang, et al., Chin. J. Chem. 43 (2025) 750–758. doi: 10.1002/cjoc.202401117
J.L. Hou, Y.X. Liu, N.H. Huang, et al., Inorg. Chem. Front. 11 (2024) 3755–3764. doi: 10.1039/d4qi00930d
Q. Cheng, M. Huang, Q.Q. Ye, et al., Chin. Chem. Lett. 35 (2024) 109112. doi: 10.1016/j.cclet.2023.109112
X. Ma, F. Sun, L. Qin, et al., Chem. Sci. 13 (2022) 10149–10158. doi: 10.1039/d2sc02886g
J. Wang, F. Xu, Z.Y. Wang, S.Q. Zang, T.C.W. Mak, Angew. Chem. Int. Ed. 61 (2022) e202207492. doi: 10.1002/anie.202207492
G. Wen, B. Ren, Y. Zheng, et al., Adv. Energy. Mater. 12 (2022) 2103289. doi: 10.1002/aenm.202103289
H.N. Zhou, Q.Y. Liu, X.Y. Chen, et al., Inorg. Chem. 63 (2024) 20501–20509. doi: 10.1021/acs.inorgchem.4c03106
S. Nitopi, E. Bertheussen, S.B. Scott, et al., Chem. Rev. 119 (2019) 7610–7672. doi: 10.1021/acs.chemrev.8b00705
W. Zhang, C. Huang, J. Zhu, et al., Angew. Chem. Int. Ed. 61 (2022) e202112116. doi: 10.1002/anie.202112116
H. Zheng, G. Wu, G. Gao, X. Wang, Chem. Eng. J. 421 (2021) 129606. doi: 10.1016/j.cej.2021.129606
P. Deng, F. Yang, Z. Wang, et al., Angew. Chem. Int. Ed. 59 (2020) 10807–10813. doi: 10.1002/anie.202000657
D. Wu, X. Wang, X.Z. Fu, J.L. Luo, Appl. Catal. B: Environ. 284 (2021) 119723. doi: 10.1016/j.apcatb.2020.119723
W. Ma, J. Bu, Z. Liu, et al., Adv. Funct. Mater. 31 (2021) 2006704. doi: 10.1002/adfm.202006704
Y.R. Wang, R.X. Yang, Y. Chen, et al., Sci. Bull. 65 (2020) 1635–1642. doi: 10.3390/ijms21051635
N. Han, Y. Wang, H. Yang, et al., Nat. Commun. 9 (2018) 1320. doi: 10.1038/s41467-018-03712-z
Y. Zhang, X. Zhang, Y. Ling, et al., Angew. Chem. Int. Ed. 57 (2018) 13283–13287. doi: 10.1002/anie.201807466
F. Yang, A.O. Elnabawy, R. Schimmenti, et al., Nat. Commun. 11 (2020) 1088. doi: 10.1038/s41467-020-14914-9
Z. Chen, K. Mou, X. Wang, L. Liu, Angew. Chem. Int. Ed. 57 (2018) 12790–12794. doi: 10.1002/anie.201807643
Y. Wang, P. Han, X. Lv, L. Zhang, G. Zheng, Joule 2 (2018) 2551–2582. doi: 10.1016/j.joule.2018.09.021
J. Yang, X. Wang, Y. Qu, et al., Adv. Energy. Mater. 10 (2020) 2001709. doi: 10.1002/aenm.202001709
J.W. Shi, S.N. Sun, J. Liu, et al., ACS Catal. 12 (2022) 14436–14444. doi: 10.1021/acscatal.2c02715
B. Hou, H. Zheng, K. Zhang, et al., Chem. Sci. 14 (2023) 8962–8969. doi: 10.1039/d3sc02924g
Y.Q. Tian, L.F. Dai, W.L. Mu, et al., Chem. Sci. 14 (2023) 14280–14289. doi: 10.1039/d3sc06046b
L.F. Dai, X.R. Liu, Y.Q. Tian, X.Y. Yi, C. Liu, Inorg. Chem. 62 (2023) 6047–6054. doi: 10.1021/acs.inorgchem.2c04528
J. Hou, Y. Liu, N. Huang, et al., Inorg. Chem. Front. 11 (2024) 3755–3764. doi: 10.1039/d4qi00930d
J. Hou, N. Huang, D. Acharya, et al., Chem. Sci. 15 (2024) 2655–2664. doi: 10.1039/d3sc05617a
L.J. Li, W.L. Mu, Y.Q. Tian, et al., Chem. Sci. 15 (2024) 7643–7650. doi: 10.1039/d3sc07005k
L.J. Li, Y.T. Luo, Y.Q. Tian, et al., Inorg. Chem. 62 (2023) 14377–14384. doi: 10.1021/acs.inorgchem.3c02083
Z. Wang, L. Li, L. Feng, et al., Angew. Chem. Int. Ed. 61 (2022) e202200823. doi: 10.1002/anie.202200823
Z. Wang, H.F. Su, Y.W. Gong, et al., Nat. Commun. 11 (2020) 308. doi: 10.1038/s41467-019-13682-5
Z. Wang, F. Alkan, C.M. Aikens, et al., Angew. Chem. Int. Ed. 61 (2022) e202206742. doi: 10.1002/anie.202206742
S. He, F. Ni, Y. Ji, et al., Angew. Chem. Int. Ed. 57 (2018) 16114–16119. doi: 10.1002/anie.201810538
Y. Xia, Z. Jin, H. Wang, et al., J. Mater. Chem. A 7 (2019) 16136–16148. doi: 10.1039/c9ta02449b
Figure 1 Crystal structures of Bi8-DMF nanocluster. (A, B) The overall structure of Bi8-DMF from different perspectives. (C) The structure of {Bi3O2@(TC4A)2} subunit. (D) The structure of {Bi5O2@(TC4A)3} subunit. (E) The Bi8O4 core (Numbers represent the coordination number of each Bi atom). Hydrogen atoms are removed for clarity.
Figure 3 Crystal structures of Bi4-Sal cluster. (A) The overall polymeric structure of Bi4-Sal. (B) The sandwich-type {Bi4O(TC4A)2} unit. Hydrogen atoms are removed for clarity.
Figure 4 Crystal structures of Bi8-Fc nanocluster. (A, B) The overall structure of Bi8-Fc from different perspectives. (C) The Bi8O4 core (Numbers represent the coordination number of each Bi atom). (D) The coordination mode of the ferrocene carboxylate. Hydrogen atoms are removed for clarity.
Figure 6 (A) LSV of samples in N2 or CO2 saturated 0.5 mol/L KHCO3 solution. (B) FE values of Bi8-DMF at different voltages. (C) FE values of Bi8-Fc at different voltages. (D) FEHCOOH comparison between Bi8-DMF and Bi8-Fc. (E) jHCOOH comparison between Bi8-DMF and Bi8-Fc. (F) Current density and FEHCOOH of Bi8-DMF during long-time electrolysis at −1.0 V (vs. RHE).
扫一扫看文章
扫一扫关注我们
DownLoad:
下载:
下载: