Aug 2026· Rare Metals· Vol 45· 0 citations· 46 references
Abstract
The electrocatalytic co‐reduction of CO
2
and nitrate () to synthesize urea presents a sustainable alternative to traditional industrial processes, yet its efficiency is fundamentally limited by the kinetically mismatched activation and coupling of CO
2
and . To address this, we designed and synthesized two insoluble trinuclear ruthenium (Ru) cluster‐anchored polyoxometalate (POM) catalysts, Ru
3
SiW
12
and Ru
3
PW
12
, in which the central heteroatom of the Keggin‐type framework (Si vs. P) serves as a key structural variable. This work reveals that the central heteroatom critically modulates the synergy within the Ru‐cluster‐ligand ensemble, which in turn governs the catalytic interface. The optimized Ru
3
SiW
12
delivers a remarkable urea yield rate of 81.6 mmol h
−1
g
cat.
−1
with a Faradaic efficiency of 56.3% at −0.30 V versus RHE, substantially outperforming its P‐centered analog. In situ spectroscopic studies combined with electrochemical analysis demonstrate that the Si‐centered framework promotes a more effective activation of interfacial water, establishing an extensive hydrogen‐bonding network that facilitates proton transfer and hydrogenation of key C‐ and N‐intermediates, thereby boosting C–N coupling. This study highlights the pivotal role of engineering synergistic metal cluster‐ligand motifs via secondary coordination sphere tuning in insoluble matrices, offering a new design strategy for advanced electrocatalysts in sustainable chemical synthesis.
Electrochemical CO2 reduction to value-added multi-carbon products is attractive, whereas the low-efficiency C─C coupling hinders the electrocatalytic selectivity and activity. Herein, we synthesize a polyphosphazene network with a precise supramolecular configuration of the neighboring dual catalytic centers by introducing dendritic molecules. The reasonable ratio of 5,10,15,20-tetrakis-(4-aminophenyl)-porphyrin-Cu-(II) and hexachlorocyclotriphosphazene results in an ultrathin polymer sheath around carbon nanotubes, exhibiting π-π stacking between the adjacent porphyrin molecules and the optimized spatial distance (3.8 Å) between the neighboring Cu active sites, featuring dual-atom catalytic centers bound to carbon nanotubes. Given the controlled geometric structure, the catalysts can boost C─C coupling reactions during CO2 electrocatalysis, thereby improving the selectivity of the multi-carbon product (EtOH) with a high Faradic efficiency (FEmax of 61.1% at -1.0 V) in broad potential windows. The strategy of achieving precise control over the spatial distance between adjacent metal catalytic centers by incorporating dendritic molecules into a polyphosphazene network provides a viable approach for designing polymer-based single-atom electrocatalysts.
The commercialization of direct alcohol fuel cells (DAFCs) is severely hindered by sluggish anodic alcohol oxidation reaction kinetics and the high susceptibility of catalysts to deactivation. Traditional Pd/Pt-based catalysts suffer from difficult C-C bond cleavage and severe CO poisoning. To address these issues, we synthesize a pentametallic PdPtNiBiCo alloy consisting of interconnected nanoparticles via a facile one-pot oil-phase method, aiming to maximize electrochemically accessible surface sites and trigger robust multimetallic synergy. This architecture delivers an exceptional alkaline ethanol oxidation activity of 16.64 A mg-1Pd+Pt, 12 and 19 times higher than those of commercial Pd/C and Pt/C, respectively. Furthermore, the catalyst exhibits robust antipoisoning durability over 4000 cycles and broad activity for methanol and ethylene glycol oxidation. Density functional theory calculations reveal that multimetallic synergy effectively modulates the d-band center of the active sites. Density functional theory calculations reveal that multimetallic synergy tunes the electronic structure of the active sites, optimizes the adsorption of key intermediates, and lowers the thermodynamic energy requirements for C-C bond cleavage and CO oxidation, thereby facilitating both the C1 and C2 pathways of ethanol oxidation. This work addresses the key limitation of traditional Pd/Pt-based catalysts and provides an effective strategy for designing high-performance universal DAFC anodes.
Guangxia Wang, Xiuwei Sun, Ruyang Geng et al.· ACS Applied Materials and In...· 0 citations
Electrocatalytic nitrogen reduction reaction (eNRR) under ambient conditions is a promising route for sustainable ammonia synthesis, yet its progress is fundamentally limited by the inertness of N≡N bonds and the lack of robust, selective catalysts. Here, we report the first synthesis of a rutile‐structured high‐entropy oxynitride (HEON, CoFeTiVSnON). By leveraging the mixing entropy of five metal elements and dual anion regulation, HEON achieves dynamically regenerable nitrogen vacancies, and a tunable electronic structure. Operando spectroscopic investigations and density functional theory (DFT) calculations reveal that HEON uniquely activates N
2
via a stabilized vacancy‐mediated quasi Mars‐van Krevelen (MvK) mechanism, wherein nitrogen vacancies directly participate in the catalytic cycle, enabling continuous vacancy formation and healing. Correspondingly, the NH
3
poisoning and vacancy depletion issues that plague conventional binary nitrides have been circumvented whilst breaking linear scaling relationship of intermediate adsorption. The HEON catalyst delivers a high NH
3
yield rate of 159.2 µg h
−1
mg
cat.
−1
and a Faradaic efficiency of 46.6% at −0.5 V vs. RHE, with good structural stability over extended operation. Our work establishes high‐entropy oxynitrides as a transformative platform for multi‐step electrocatalysis, and provides mechanistic insights for the rational design of catalysts stabilized by high entropy effects.
Yiwen Su, Xinzhong Wang, Jinjin Wu et al.· Advanced Functional Material...· 0 citations
Cyclohexanone oxime (CHO) is a vital precursor in industrial synthesis of nylon-6. However, traditional synthetic routes involve harsh reaction conditions and the potential danger posed by explosive hydroxylamine. Herein, we introduce an electrocatalytic approach for CHO synthesis via the reductive coupling of cyclohexanone (CYC) and nitrite using an electrocatalyst (FeNP@FeSA-N(OH)-B-C), which features a synergistic modulation of Fe single atoms (Fe SAs) by axial coordinated OH, second-shell coordinated boron (B), and adjacent Fe nanoparticles on a nitrogen-doped carbon support. In a membrane electrode assembly electrolysis cell, the FeNP@FeSA-N(OH)-B-C achieves a Faradaic efficiency for CHO of 63.97% and a CHO yield rate of 0.629 mmol h-1 cm-2 at 100 mA cm-2, maintaining exceptional stability over 110 h of continuous operation. In situ characterizations reveal formation of electron-deficient Fe SAs with a Fe-N(OH)-B structure. Density functional theory calculations demonstrate that Fe-N(OH)-B facilitates the *NO → *NOH → *NHOH → *NH2OH reaction pathways while it inhibits *NH2OH reduction to NH3, collectively promoting the activity and selectivity of electrochemical CHO synthesis. This work not only presents a highly efficient and stable electrocatalyst for sustainable CHO synthesis but also provides insights into the dynamic control of coordination environment of SAs for enhanced electrocatalytic performance.
Junchao Yu, Qing-Jin Li, Meng-Yu Li et al.· ACS Nano· 0 citations
The electrochemical reduction reaction of CO (eCORR) to acetate is a pivotal pathway for carbon neutrality, yet it is persistently constrained by the linear scaling relations of the adsorption energetics of key intermediates. Consequently, conventional alloy catalysts often suffer from an activity-selectivity trade-off, failing to stabilize C─C coupling intermediates without poisoning active sites. Herein, we circumvent this thermodynamic limit by constructing atomically asymmetric Pd1─O─Cu interfaces derived from the partial operando reconstruction of a metal-organic framework (CuPd-THQ), where isolated Pd single atoms are anchored on Cu2O nanoislands (Pd/Cu2O/CuPd-THQ). The strong CO affinity of Pd drives the migration of remote *CO species toward the Pd center via a spillover effect. This catalyst achieves an industrial-level acetate Faradaic efficiency of 82.3% (purity of 96%) and sustains performance for over 400 h at 250 mA cm-2 under -1.0 V versus RHE, significantly outperforming conventional Cu-based catalysts. Furthermore, in a membrane electrode assembly (MEA) system, it delivers a remarkable acetate yield rate of 6367.7 mg L-1 h-1, demonstrating scalable viability. Mechanism studies reveal that this atomic-scale geometric isolation allows for the independent optimization of *CO and *CCO binding energetics. Our findings provide a generalizable strategy for breaking scaling relations in complex multi-electron electrocatalysis.
Covalent organic frameworks (COFs) have attracted considerable attention as promising photocatalysts for hydrogen peroxide (H2O2) production. To further improve their catalytic performance, a quaternary ammonium functionality was introduced into the bipyridine units of the COF via a post-synthetic modification strategy. Under identical irradiation conditions, the cationized Pry-COF-QA achieved a H2O2 production rate of 7.31 mmol·h–1·g–1, which is markedly higher than that of the non-protonated Pry-COF (5.50 mmol·h–1·g–1). To gain mechanistic insight into the enhanced activity, density functional theory (DFT) calculations were performed. The results indicate that the incorporation of the quaternary ammonium group fundamentally reconfigures the photophysical behavior. In addition to inducing a red shift in the absorption spectrum by narrowing the HOMO–LUMO energy gap, it more importantly converts the excitation character from a localized excitation (LE) state, which is unfavorable for charge separation, to an intramolecular charge transfer (ICT) state with well-separated spatial distribution. This efficient ICT pathway effectively suppresses electron–hole recombination, thereby significantly prolonging the lifetime of photogenerated charge carriers and ultimately facilitating efficient photocatalytic H2O2 production, while also providing a valuable guideline for the rational design of COF-based systems toward efficient photocatalytic H2O2 generation.
Zhihui Sun, Jiajia Li, Long-Yang Yang et al.· ACS Applied Energy Materials· 0 citations
