Key Takeaways & Executive Findings
- •• • The M-Ir/ACN system achieves a 20-fold increase in CO production compared to pristine ACN, demonstrating a substantial enhancement in photocatalytic CO2 reduction efficiency. • • Sustained stability over 45 hours of continuous operation indicates robust performance, critical for practical solar-to-fuel applications where catalyst longevity is a major economic factor. • • Time-resolved in situ spectroscopy captures rapid carbamate intermediate transformation and sustained IrOOH formation, providing direct evidence of the synergistic mechanism and guiding rational design of dual-site catalysts. • • Microkinetic modeling reveals that the MEA-Ir system creates interconnected H spillover networks, facilitating efficient proton transport that drives *COOH formation with favorable thermodynamics, addressing the bottleneck of proton supply in CO2 photoreduction.
Abstract
Construction of metal-mediated redox sites is an appealing approach to enhance photocatalytic CO2 reduction coupled with H2O oxidation. However, conventional static redox sites generally lack spatiotemporal matching during reaction processes due to the constraints of rigid structure and the linear scaling relationship of adsorbed species. Herein, an alkanolamine-Ir synergistic system was developed, where flexible monoethanolamine (MEA) molecules function as molecular ferries to selectively adsorb CO2 via carbamate formation, while adjacent Ir nanoparticles (NPs) serve as H spillover hubs that relay protons, creating spatiotemporal adaptability that synchronizes CO2 reduction and water oxidation. In addition, time-resolved in situ spectroscopy directly captures the rapid transformation of carbamate intermediates concurrent with sustained IrOOH intermediates formation. Microkinetic modeling further demonstrates that the MEA-Ir modified system (M-Ir/ACN) creates interconnected H spillover networks between Ir NPs and MEA, facilitating efficient proton transport that drives *COOH formation with a favorable thermodynamic energy. As a result, the M-Ir/ACN achieves a 20-fold increase in CO production compared to the pristine sample while maintaining high stability throughout 45 h of continuous operation. This study presents that flexible molecular ferries boost CO2 adsorption, and deciphers how flexible molecular-metal synergy directs the trafficking of CO2-derived intermediates toward highly efficient CO2 photoreduction.
1. Introduction
Photocatalytic CO2 reduction coupled with water oxidation offers a dual benefit of carbon-negative fuel production and renewable energy storage, yet conventional single-site catalysts suffer from insufficient CO2 adsorption and inefficient proton supply, leading to high energy barriers for critical intermediates like *COOH and predominant H2 evolution. Metal-mediated dual-active sites have been explored, but rigid coordination structures and linear scaling relationships impose spatiotemporal mismatches, limiting synergistic CO2 reduction and water oxidation.
This work introduces a flexible alkanolamine-Ir synergistic system where monoethanolamine (MEA) acts as a molecular ferry for CO2 capture via carbamate formation, while adjacent Ir nanoparticles serve as proton relay hubs via hydrogen spillover. This design creates spatiotemporal adaptability, synchronizing the two half-reactions. The M-Ir/ACN catalyst achieves a 20-fold increase in CO production and maintains stability over 45 hours, demonstrating a viable strategy to overcome the limitations of static redox sites.
Loading authentic research manuscript (Pages 1–5)...
Qiaolin Wu, Xingyu Liu, Lei Cheng, Yawen Tang, Yafei Li, Yu Wang, Hanjun Sun (2026). Synergistic Mediation: Flexible Alkanolamine-Ir Sites for Photocatalytic CO2 Reduction Coupled with Water Oxidation. SCIENCE CHINA Materials. https://doi.org/10.1007/s40843-025-3702-0
Research & Educational Purpose Only: The translations, structured abstracts, analytical annotations, and data reports provided by SinoGreenTechare intended exclusively for academic research, internal corporate R&D, and educational benchmarking. They do not constitute formal engineering, chemical safety, legal, or professional advice.
Copyright & Intellectual Property Notice: Original copyright of the underlying source articles and experimental data remains with the respective authors, institutions, and original publishing journals. SinoGreenTech claims intellectual property only over its proprietary translations, analytical syntheses, and AEO structured enhancements in accordance with international fair use and academic citation principles.
Frequently Asked Questions
What is the specific role of monoethanolamine (MEA) in enhancing CO2 adsorption and how does it interact with Ir nanoparticles to facilitate proton transfer?
MEA acts as a flexible molecular ferry that selectively adsorbs CO2 via carbamate formation, increasing local CO2 concentration. Adjacent Ir nanoparticles serve as H spillover hubs, relaying protons generated from water oxidation to the carbamate intermediates, thus facilitating the formation of *COOH and subsequent CO production. This synergistic interaction creates interconnected H spillover networks that enhance proton transport.
How does the M-Ir/ACN system achieve a 20-fold increase in CO production compared to pristine ACN, and what are the underlying kinetic or thermodynamic factors?
The 20-fold increase is attributed to the synergistic effect of MEA and Ir: MEA enhances CO2 adsorption, while Ir promotes proton transfer via H spillover. Microkinetic modeling indicates that the MEA-Ir system lowers the thermodynamic energy barrier for *COOH formation, a key intermediate in CO2 reduction, thereby improving reaction kinetics and selectivity toward CO.
What evidence supports the claim of spatiotemporal adaptability in the MEA-Ir system, and how does this overcome limitations of conventional static redox sites?
Time-resolved in situ spectroscopy directly captures the rapid transformation of carbamate intermediates concurrent with sustained IrOOH formation, indicating that the flexible MEA molecules and Ir NPs dynamically coordinate CO2 reduction and water oxidation. This adaptability contrasts with rigid static sites that suffer from spatial and temporal mismatches, as the flexible MEA can adjust its conformation to facilitate intermediate conversion.
What is the long-term stability of the M-Ir/ACN catalyst under continuous operation, and are there any signs of deactivation or structural changes?
The M-Ir/ACN catalyst maintains high stability throughout 45 hours of continuous operation, with no significant loss in CO production. This suggests robust structural integrity and resistance to deactivation, which is critical for practical applications. However, detailed post-reaction characterization would be needed to assess any subtle changes in the catalyst structure.
How does the M-Ir/ACN system compare to other state-of-the-art photocatalytic CO2 reduction systems in terms of CO production rate and selectivity?
The paper reports a 20-fold increase in CO production compared to pristine ACN, but does not provide absolute rates or selectivity values in the abstract. To benchmark against other systems, one would need to refer to the full paper for specific metrics such as μmol g−1 h−1 and CO selectivity. The stability over 45 hours is notable, but direct comparisons require additional data.
Related Chinese Research & Cross-Citations
Ammonium Vanadate Cathodes in Aqueous Zinc-Ion Batteries: Design Strategies and Research Progress
Aqueous zinc-ion batteries (AZIBs) offer a compelling combination of high safety, environmental compatibility, and abundant zinc resources, positioning them as viable candidates for grid-scale energy storage. Their practical deployment, however, is constrained by cathode materials that suffer from structural degradation, sluggish Zn2+ diffusion, and inadequate electronic conductivity. Ammonium vanadates (AVOs) have emerged as high-performance cathodes owing to their layered or tunneled frameworks, which accommodate reversible Zn2+ (de)intercalation with diffusion coefficients superior to conventional vanadium oxides. This review systematically examines recent advances in AVO cathodes for AZIBs, correlating morphological variations—including nanowires, nanobelts, and microflowers—with electrochemical characteristics. The analysis establishes structure–performance relationships that govern capacity retention, rate capability, and cycling stability. Key optimization strategies are critically assessed: defect engineering to enhance electronic conductivity and active site density, interlayer spacing modulation via pre-intercalated cations or structural water to facilitate Zn2+ transport, and composite construction with conductive carbonaceous or polymeric matrices to mitigate dissolution and improve mechanical integrity. Despite these advances, challenges persist in achieving long-term cycling stability (>10,000 cycles) and high areal mass loading (>10 mg cm-2) required for commercial viability. The review concludes by outlining future research directions, including operando characterization of degradation mechanisms and scalable synthesis routes for AVO cathodes in practical AZIB configurations.
Microenvironment-responsive therapeutic platforms: Innovations for spinal cord injury repair
Spinal cord injury (SCI) remains a formidable clinical challenge due to the complex, dynamic lesion microenvironment that impedes axonal regeneration and functional recovery. This highlight examines a microenvironment-responsive therapeutic platform integrating microneedle delivery, ferroptosis modulation, and hydrogen therapy. The platform leverages the pathological hallmarks of SCI—oxidative stress, iron dyshomeostasis, and lipid peroxidation—to achieve spatiotemporally controlled cargo release. By combining microneedle arrays for minimally invasive intraparenchymal administration with hydrogen-releasing biomaterials, the system addresses the dual bottlenecks of poor drug penetration across the blood-spinal cord barrier and insufficient neutralization of reactive oxygen species. Ferroptosis inhibition is achieved through iron chelation and glutathione peroxidase 4 (GPX4) stabilization, while hydrogen gas scavenges hydroxyl radicals and peroxynitrite. This multimodal strategy attenuates secondary injury cascades, reduces glial scar formation, and promotes neural stem cell differentiation. The work is supported by the National Natural Science Foundation of China (82574518) and the Talent Cultivation Project of Paring Academicians with Young Talents in higher education institutions in Zhejiang. The authors declare no conflict of interest. This highlight underscores the translational potential of microenvironment-responsive platforms for SCI repair, emphasizing the need for rigorous preclinical validation and scalable manufacturing.
Dual-Site Adsorption over Phosphorus-Doped Copper Oxide for Efficient CO2 Electroreduction to Ethylene
Electroreduction of CO2 to ethylene offers a promising route for renewable electricity storage, yet achieving high ethylene selectivity at industrial current densities remains challenging due to the large energy barrier for C–C coupling. Here, we report a “MOF-assisted in situ doping” strategy to introduce the oxophilic nonmetal phosphorus (P) into the copper oxide (CuO) lattice, constructing a localized Cu–P dual-site adsorption configuration for the key *OCCHO intermediate. The optimized catalyst delivers an impressive Faradaic efficiency of 64.6% for ethylene with a partial current density of 646 mA cm-2. Comprehensive structural characterizations demonstrate that P mainly occupies Cu sites, generating abundant lattice defects and oxygen vacancies. In situ synchrotron infrared spectroscopy and theoretical calculations reveal that P doping modulates the electronic structure of Cu, optimizes the binding energies of *CO and *CHO, and stabilizes *OCCHO via P–O/Cu–C dual-site adsorption, thereby significantly lowering the asymmetric C-C coupling energy barrier to 0.74 eV. This work highlights a dual-site microenvironment regulation strategy for CO2-to-ethylene electroreduction.
Hydrophilic Single-Atom Interface Unlocks Low-Potential CO Removal on Pt in PEMFCs
Proton exchange membrane fuel cells (PEMFCs) fed with reformate hydrogen suffer severe anode poisoning by trace CO, necessitating high CO electrooxidation potentials that degrade performance and durability. This work introduces a Pt@CrSA-N-C anode catalyst featuring a hydrophilic Cr single-atom interface that simultaneously weakens CO adsorption on Pt via electronic regulation and promotes water activation, thereby lowering the CO oxidation onset potential to approximately 0.13 V vs. RHE. The onset potential was determined by two independent methods: the first potential at which the background-corrected current exceeds 0 mA cm-2 during CO oxidation reaction tests in a three-electrode system, and the potential at which the forward scan current exceeds the N2 background current in CO-stripping voltammetry. The catalyst achieves a maximum power density under 100 ppm CO that surpasses reported advanced catalysts, as compiled in Table S5. Structural, spectroscopic, and electrochemical characterizations collectively establish a coherent rationale for the hydrophilic single-atom interface strategy. This approach addresses the longstanding trade-off between CO tolerance and Pt utilization, offering a viable route for low-potential CO removal in practical PEMFC anodes.
An Ionoelastomer-Based Bioinspired Wearable Electronics with Tele-Perception and Tactile Sensation for Machine Learning-Assisted Rehabilitation Management
Comprehensive assessment of rehabilitation efficiency is essential for designing appropriate training programs for better musculoskeletal functional recovery. Existing contact-receptor-dependent rehabilitation assessment systems mostly focus on assessing the restoration of muscle function by evaluating grip strength or joint flexion angle; however, parameters reflecting neuromuscular synergistic function are always overlooked. Herein, we develop an ionoelastomer-based soft artificial electroreceptor (SAER) that integrates tele-perception and tactile sensation to track the rehabilitation process, collecting signals related to approaching speed and grip strength sequentially. The SAER uses polyurethane ionoelastomer incorporated with quasi-solid conductive salt as the electric field receptor, and is integrated on a rehabilitation-training ball after assembly to establish an untethered detection device; this enables the remote capture of hand approaching parameter within a 9 cm range, followed by the quantification of grip strength when contacting and grasping. Furthermore, a data-driven assessment system is established by integrating machine learning, which accurately classifies rehabilitation efficiency into six levels; it supports for rehabilitation evaluation and training programs adjustment. Overall, the SAER-based rehabilitation management system establishes a paradigm that synergistically evaluating parameters corresponding to neuromuscular functional restoration and holds strong potential for home-based active rehabilitation for minimizing dependence on frequent clinical supervision.
Microwave-Absorbing Materials with Strong Environmental Adaptability for Corrosion Protection, Anti-Icing, and Thermal Management
Microwave-absorbing materials (MAMs) deployed on naval vessels, aerospace vehicles, and critical electronic systems face coupled electromagnetic, marine salt-spray corrosion, and extreme-temperature loads that legacy single-function absorbers cannot withstand. This review consolidates progress on three environmentally adaptive MAM classes: corrosion-protective, anti-icing, and thermal-management absorbers. The electromagnetic loss and impedance-matching fundamentals are first established, then the synergistic mechanisms, design strategies, and characterization protocols for each class are examined against representative material systems and their measured performance. The analysis identifies a shared design logic—multiscale hierarchical architecture, interfacial polarization engineering, and multifunctional phase integration—while distinguishing the divergent protection mechanisms: barrier and passivation effects for corrosion, surface-energy and latent-heat regulation for anti-icing, and phonon–electron transport decoupling for thermal management. Persistent bottlenecks include the trade-off between impedance matching and protective-layer density, the absence of standardized coupled-field test protocols, and the scarcity of long-term salt-spray and thermal-cycling durability data. Future directions are delineated: intelligent self-adaptive absorbers, multiphysics-coupled simulation frameworks, and environmentally benign multifunctional integration. The review provides a theoretical and technical basis for the design, construction, and engineering scale-up of next-generation high-performance absorbers for aerospace, electronic, and marine equipment.