Stable Catalyst Research Articles

Hydrogenation of CO2 to light olefins over Ga2O3-ZIF-8 tandem catalyst

Tandem catalysts composed of metal oxides and zeolites have demonstrated significant potential for the hydrogenation of CO2 to light olefins. However, their development is hindered by the competing reverse water–gas shift reaction and carbon accumulation on the zeolite surface. To address these challenges, we developed a series of innovative tandem catalysts by substituting conventional zeolites with ZIF-8. Our research primarily focused on examining the effects of metal species and content, as well as the particle size of ZIF-8, on catalytic performance. Notably, we achieved a CO2 conversion of 20.2 % and a light olefins selectivity of 73.6 % using a catalyst with 20 % Ga2O3 content and a ZIF-8 particle size of 100 nm at a reaction temperature of 340 °C and pressure of 3.0 MPa. In order to improve the stability of the catalyst, ZIF-8 was modified with La to improve its thermal stability. A CO2 conversion of 23.5 % and a light olefins selectivity of 66.5 % were maintained after 50 h of continuous reaction. While the catalytic activity of La-modified catalysts is slightly lower than that of unmodified ones, their superior stability makes them more suitable for thermal catalytic hydrogenation of CO2. Various characterizations and theoretical calculations revealed that La modification not only enhanced the thermal stability of catalyst but also improved its adsorption and activation capabilities for the reacting gases. Furthermore, the reaction mechanism of CO2 hydrogenation to light olefins was investigated by in-situ diffuse reflectance Fourier transform infrared spectroscopy. This study provides a technical foundation for designing efficient catalysts based on metal–organic frameworks in the field of carbon dioxide thermal catalytic conversion.

Engineering porous clay nanoarchitectures from unusual commercial organoclay: Supported manganese oxide as stable catalysts in the total oxidation of volatile organic compounds

The porous engineering of clay nanoarchitectures (PCN) achieved from a well-known but little-explored commercial organoclay C-20A is reported. Thorough characterizations (by XRD, TGA, N2 sorption, ICP, SEM, TEM, 27Al MAS NMR, DR UV-Vis, XPS, Py-FTIR and H2-TPR) confirmed a delaminated structure presenting a specific surface area of 504 m² g−1, twelve times higher than the sodic montmorillonite used as reference and featuring a new pore system comprising a size range from supermicropores to small mesopores (1.3–10 nm). The role of these PCN as support of manganese oxide for the gas-phase total catalytic oxidation of volatile organic compounds (VOCs) was evaluated. PCN with 5 % of Mn resulted in a higher nanoparticle dispersion (10 nm) compared to the sodic montmorillonite (17 nm). The highest catalytic activity was reached with PCN containing 10 % of Mn achieving a benzene, toluene and ortho-xylene oxidation of 54 %, 39 % and 34 %, respectively, at 350 °C. The catalyst was stable up to 36 h under these conditions.

Facile construction of a stable biomass-derived carbon-supported AlZr composite with crystalline solid solution and Brønsted-Lewis dual acidity for efficient catalytic conversion of cellulose.

Exploiting cellulose-derived levulinic acid (LA) in biorefinery has potential application prospects, and the development of efficient and stable catalysts is crucial yet challenging. In this study, a bimetallic synergy strategy was proposed to construct an efficient and durable solid acid catalyst with crystalline solid solution by a totally solid-phase method. Mechanical activation (MA)-treated precursor (metal salts, starch, and urea) was calcined to obtain a stable biomass-derived carbon (BC)-supported AlZr (MA-AZ/BC) composite, which was applied for catalytic conversion of cellulose to LA in aqueous-phase system. The results indicate that the synergistic effect of bimetallic crystalline solid solution and the existence of Brønsted-Lewis dual-acid sites in the MA-AZ/BC catalyst contributed to a cellulose conversion efficiency of 97.5% and a LA yield of 67.1%. Benefiting from the strong bimetal-support interaction, the MA-AZ/BC catalyst exhibited favorable stability and recoverability. On the basis of comprehensive analysis, a reaction mechanism of Brønsted-Lewis dual-acid sites for synergistic catalytic conversion of cellulose was proposed. This study provides a new idea for the rational design and environmentally friendly fabrication of functional BC-based catalysts for efficiently producing platform compounds derived from biomass.

Unlocking OER potential: Tailoring layered double perovskites through self-reconstruction

The sluggish rate of the anode oxygen evolution reaction (OER) is a major bottleneck for green hydrogen production, making a room-temperature alkaline water electrolyser critical to unlocking the full potential of this technology. Using a perovskite oxide as an electrochemical matrix and forming a self-assembled oxyhydroxide (OOH) layer on the surface via a self-reconstruction activation process (SRAP) is a promising strategy to enhance OER catalytic activity. However, the mechanistic details and long-term impact of SRAP, especially its relationship to catalytic activity, oxygen collection efficiency, and catalyst dissolution, are not fully understood. To address this knowledge gap, we used layered double perovskite (LDP) PrBa0·75Ca0·25Co1·5Fe0·5O5+δ(PBCCF) and PrBa0·75Ca0·25Co1·5Fe0·4Ni0·1O5+δ (PBCCFN) as model electrochemical catalysts and then triggered SRAP. Subsequently, chronoamperometry (CA), rotating ring disk electrode (RRDE) and in-situ electrochemical quartz crystal microbalance (EQCM) were used to study the effect of the Ni-doping on PBCCF SRAP in terms of catalytic activity, oxygen collection efficiency and catalyst stability. The results showed that the OER catalytic current of the LDP PBCCF and PBCCFN was enhanced via SRAP and the oxygen collection efficiency can be maintained, suggesting that the increase in catalytic current is attributed to OER catalytic activity increase rather than electrochemical catalyst dissolution. Additionally, the effect of the catalytic activity enhancement was more significant in PBCCFN. More importantly, the stability of the LDP PBCCF and PBCCFN after SRAP are higher than simple perovskite Ba0·5Sr0·5Co0·8Fe0·2O3-δ (BSCF) because of the increase in the redeposition rate. The observations suggest that using LDP PBCCF and PBCCFN as matrices followed by triggering SRAP can provide valuable insights for designing LDP based OER electrocatalysts.

Cr-MIL-101 derived nano Cr2O3 for highly efficient dehydrogenation of n-hexane

Nano Cr2O3 (n-Cr2O3) was prepared by the thermolysis of the mesoporous Cr-MIL-101, and its catalytic performance for n-hexane dehydrogenation was investigated and compared with Cr2O3 obtained by traditional method. It is found that dehydrogenation of n-hexane on n-Cr2O3 catalyst can produce n-hexenes and benzene efficiently, and the catalytic performance is related to the calcination temperature. The optimal n-hexane conversion can be obtained on n-Cr2O3 calcinated under 600 °C, is 40.6%, and the selectivities to n-hexenes and benzene are 20.1% and 69.3%, respectively. The conversion of n-hexane for n-Cr2O3 catalyst is decreased with calcination temperature increase, while the catalyst stability in dehydrogenation reaction is enhanced. n-Hexane conversion of p-Cr2O3-1 (obtained by precipitation method) and p-Cr2O3-2 (calcinating Cr(NO3)·9H2O directly) catalysts are very low (<7.5%), and their specific activity for n-hexane dehydrogenation are 1.5 and 1.7 g/(m2·h) respectively, lower than that of n-Cr2O3-600 (2.0 g/(m2·h)). The results of BET, XRD, TEM and FT-IR reveal that n-Cr2O3 is the nanoparticles with large specific surface area that more dehydrogenation active sites are exposed, while p-Cr2O3 is the large particles with extremely low surface area that few dehydrogenation active sites are presented. By contrast, industrial Cr2O3/Al2O3 catalyst possesses the highest specific activity of 2.4 g/(m2·h) due to the dispersion effect of Al2O3. Therefore, highly catalytic activity of n-Cr2O3 for n-hexane dehydrogenation is attributed to the unique properties of small particle, large specific surface area and more exposed active sites. This work not only explains the high dehydrogenation activity of nano-Cr2O3 derived by Cr-MIL-101, but also provides guidance for the precise design and synthesis of high-performance CrOx-based catalyst for the dehydrogenation of alkanes.

Establishing metal-nonoxygen bonds to improve thermal stability of Pt1/CeO2 via coating boron nitride

Supported metal catalysts are pivotal in the chemical industry, but achieving high activity while maintaining atomically dispersed status to maximize atom efficiency under harsh conditions remains a formidable challenge. In this study, we present a synthetic strategy to enhance the stability of ceria-supported Pt catalysts by coating them with an inert layer of boron nitride (Pt1/CeO2@BN). The BN layer serves to stabilize and modulate the dispersion and electronic state of Pt species, as well as the oxygen vacancy concentration of CeO2. Consequently, the Pt1/CeO2@BN catalyst maintained the atomically dispersed status of Pt species under high-temperature oxidative (900 °C for 3.5 h in air) and reductive (1000 °C for 1 h in H2) conditions and increased the turnover frequency for CO oxidation by four times at 140 °C. Our work offers a valuable strategy to enhance the thermal stability of supported metal catalysts under harsh reaction conditions.

Functionalization of Graphene Oxide with Guanidine: Synthesis, Characterization and Catalytic Potential in Aldol and Knoevenagel Condensation Reactions

AbstractHerein, we synthesized guanidine functionalized graphene oxide nanocomposites referred to GO‐GN NCs using hummer's method. GO‐GN NCs was characterized using Fourier‐Transform Infrared Spectroscopy, Powder X‐ray Diffraction, Thermogravimetric Analysis, Raman Spectroscopy, Field Emission Scanning Electron Microscopy, Transmission Electron Microscopy, Brunauer‐Emmett‐Teller (BET) surface area analysis to confirm successful formation of GO‐GN NCs catalysts. The catalytic performance for GO‐GN NCs was evaluated for Knoevenagel and Aldol condensation reaction in aqueous medium at ambient condition and result shows that it could be used as a highly efficient, stable, and durable catalyst. In addition, it has another feature such as easy workup procedure, large substrate tolerance, high reaction yield, good recyclability, and environmental friendliness.

Quantum confinement for stable nickel catalyst in hydrogen oxidation

Quantum confinement for stable nickel catalyst in hydrogen oxidation

1-Dimensional metal Nitride-Supported platinum nanoclusters for Low-Temperature hydrogen production from formic acid

Formic acid is widely recognized as a suitable liquid hydrogen carrier for linking renewable energies toward various economic sectors. Designing efficient and stable heterogeneous catalysts for low-temperature hydrogen generation from formic acid is vital for this topic. In this study, a rational hierarchical architecture is explored by assembling Pt nanoclusters with 1-dimensional (1D) GaN nanowires. The catalytic architecture describes a considerable hydrogen production activity of 54.89 mmol·gcat−1·h−1 with a nearly 100 % selectivity and a turnover frequency (TOFPt) of 505.7 h−1 under near ambient condition, enables the achievement of a high turnover number of 306,981 mol H2 per mole Pt over 200 h of long-term operation. Through comprehensive mechanistic studies, it is unraveled that the synergistic effect between Pt nanoclusters and GaN significantly reduces the energy barrier for the formation of the key HCOO* intermediate from formic acid dehydrogenation whereas significantly increase the energy barrier of HCOOH → HCO* + *OH. It thus simultaneously contributes to improving the activity and selectivity of formic acid decomposition toward H2. This study proposes a promising strategy for hydrogen generation from formic acid at low temperatures, which is critical for achieving carbon neutrality by coordinating industrial waste heat with renewable energies via liquid hydrogen carriers.

Electrocatalysis of Co/CoxOy nanofilms supported by synchronously nitrogen-doped Ketjenblack carbon towards oxygen reduction reaction

Developing a highly active and stable non-precious metal catalyst for oxygen reduction reaction (ORR) is of great practical significance for advancing fuel cell technology. In this work, a continuous two-step hydrothermal reaction followed by high temperature pyrolysis were employed to achieve in situ N-doping preferentially into Ketjenblack carbon (KB-N) and composite of KB-N and Co/CoxOy nanofilms (Co/CoxOy-NFs) as Co/CoxOy-NFs@KB-N. The N-doped state strongly affects the ORR activity of catalyst. All prepared Co/CoxOy-NFs@KB-N catalysts exhibit observably improved ORR activity compared with the basal KB-N and N-doped Co/CoxOy-NFs, in which the optimal Co/CoxOy-NFs@KB-N catalyst demonstrate the positive Eonset (0.864 V) and E1/2 (0.788 V) vs. RHE, the low Tafel slope (69.27 mV dec−1), implying quick ORR kinetics. And, the Co/CoxOy-NFs@KB-N catalyst exhibits highly electrochemical durability. The KB-N substrate can purify Co valence in CoO component, promote amorphization of CoO crystalline structure and enhance the interaction between Co/CoxOy-NFs and KB-N in Co/CoxOy-NFs@KB-N catalyst. Thus electronic effect, structural effect and synergistic effect can strengthen O2 adsorption, provide enough adsorbed sites and accelerate electron transfer, resulting in prominent ORR performance of Co/CoxOy-NFs@KB-N catalyst.

Revolutionizing Nitrogen Electrocatalysis: Atomically Dispersed Ruthenium Catalyzed by Manganese for Unmatched Performance

Seeking sustainable ammonia, the electrocatalytic nitrogen reduction reaction (NRR) via electrocatalysis is crucial but challenged by catalyst efficiency and stability needs. This study presents RuMn-NC@NF, a novel bimetallic ruthenium-manganese catalyst synthesized via chemical vapor deposition (CVD), featuring atomically dispersed active sites on porous carbon. The strategic incorporation of manganese into the ruthenium lattice modulates the electronic structure, optimizing nitrogen adsorption and accelerating reaction kinetics. Our results demonstrate that RuMn-NC@NF achieves a remarkable Faradaic efficiency of 33.37% and an ammonia yield rate of 187.06μgh-1 mgcat.-1. XRD, SEM, HAADF-STEM, and XPS characterizations affirm the atomic distribution and elemental makeup of the catalyst. Meanwhile, DEMS and DFT calculations reveal the intrinsic mechanisms driving the reaction. The RuMn-NC@NF catalyst exhibits excellent stability over multiple cycles, underscoring its potential for practical and sustainable ammonia production. This research advances electrocatalysis with an innovative NRR catalyst for sustainable applications.

Electronic interactions between neighboring functionalized guest Sb single atoms and Pt clusters enhance CO tolerance

Platinum-based (Pt) catalysts are notoriously susceptible to deactivation in industrial chemical processes due to carbon monoxide (CO) poisoning. Overcoming this poisoning deactivation of Pt-based catalysts while enhancing their catalytic activity, selectivity, and durability remains a major challenge. Herein, we propose a strategy to enhance the CO tolerance of Pt clusters (Ptn) by introducing neighboring functionalized guest single atoms (such as Fe, Co, Ni, Cu, Sb, and Bi). Among them, antimony (Sb) single atoms (SAs) exhibit significant performance enhancement, achieving 99% CO selectivity and 33.6% CO2 conversion at 450 °C. Experimental results and density functional theory (DFT) calculations indicate the optimization arises from the electronic interaction between neighboring functionalized Sb SAs and Pt clusters, leading to optimal 5d electron redistribution in Pt clusters compared to other functionalized guest single atoms. The redistribution of 5d electrons weaken both the σ donation and π backdonation interactions, resulting in a weakened bond strength with CO and enhancing catalyst activity and selectivity. The redistribution of 5d electrons weaken both the σ donation and π backdonation interactions, resulting in a weakened bond strength with CO. In situ environmental transmission electron microscopy (ETEM) further demonstrates the exception thermal stability of catalyst, even under H2 at 700 ℃. Notably, the functionalized Sb SAs also improve CO tolerance in various heterogenous catalysts, including Co/CeO2, Ni/CeO2, Pt/Al2O3, and Pt/CeO2-C. This finding provides an effective approach to overcome the primary challenge of CO poisoning in Pt-based catalysts, making their broader applications in various industrial catalysts.

CO2(OH)2CO3 and Fe doped Co2(OH)2CO3 prepared as efficient and stable catalysts for activation of PMS: Two systems comparison and key role of high-valent metal-oxo species in mechanism revealing

High-valent metal-oxo species [M(IV) = O] exhibited high selectivity and chemical efficiency in advanced oxidation processes for removing organic pollutants, making their manipulation essential in catalytic systems. However, the low and unsustainable efficiency of generating M(IV) = O posed significant challenges. In this research, Co2(OH)2CO3 were successfully prepared via a one-pot hydrothermal method to efficiently activate peroxymonosulfate (PMS) with high-valent cobalt-oxo species [Co (IV) = O] as the primary active oxidation species. Building upon this foundation, COC was modified through variations in metal types and elemental ratios, in which magnetically enriched FexCo2-x(OH)2CO3 was synthesized by gradient Fe doping with higher catalytic efficiency and stability. The insertion of Fe resulted in the lengthening of the Co-O bond and improved the valence distribution of cobalt on the COC surface. Besides, it enabled part of the electrons to be transferred from the Fe active center to the Co active center, breaking the limitation of the traditional two-electron transfer and realizing the stable generation of more high-valent metals. Both reaction systems achieved efficient degradation of sulfadimethoxine (SDM) within 30 min and were able to completely degrade SDM within 30 min even after three cycles. FexCo2-x(OH)2CO3 maintained excellent catalytic performance even after 30 days of exposure to air. In both systems, high-valence metals played a dominant role, while the contributions of hydroxyl radicals and sulfate radicals were negligible. Overall, the two groups of developed catalysts both showed remarkable stability and pollutant removal performance in anions, humic acid, Different antibiotics and real water systems, which provided a new perspective on antibiotic removal.

Modulating the electronic interaction of ZnFemCrOx/SAPO-34 to boost CO2 hydrogenation to light olefins

Hydrogenation of CO2 into light olefins presents a promising strategy to realize carbon neutrality. Efficient adsorption and activation of CO2 are critical steps in CO2 hydrogenation into light olefins. Nevertheless, the development of a promotional catalyst that obtains high CO2 conversion and C2=-C4= selectivity is challenging, constrained by the chemical inertness of CO2. In this paper, we have synthesized a highly stable catalyst consisting of ZnFe0.38CrOx oxides and SAPO-34 zeolite, which achieves 11.4 % C2=-C4= yield at CO2 conversion up to 35.4 %. Comprehensive characterization results substantiate the existence of electronic interaction among Fe, Zn, and Cr, which facilitates the adsorption and activation of CO2. More significantly, the CO2 adsorption capacity is linearly related to the degree of electron transfer. In situ DRIFTS results further reveal that electronic interaction promotes the production of carbonate species and subsequent transformation into formate species, contributing to high CO2 conversion. These findings uncover an intrinsic connection between electronic interaction and catalytic activity, offering theoretical guidance for designing bifunctional catalysts.

Copper-PANI-graphite HB2 composite for eco-friendly efficient degradation of textile dyes: Advancements in wastewater treatment enhanced by solar radiation

This research aimed to assess the potential of Cu50PANI@UG composite for sunlight drive photocatalytic dye degradation, targeting specifically Thymol Blue (TB) and Black NT (BNT) dyes and their mixture (DM). The Cu50PANI@UG composite was successfully synthesized via electropolymerization in acetonitrile/sulfuric acid mixture under atmospheric conditions. Photocatalytic experiments were conducted by exposing aqueous dye solutions to sunlight. N,N-dimethyl-p-nitrosoaniline (RNO) served as a molecular probe for detecting hydroxyl radicals (•OH). Additionally, experiments capturing free radicals were performed to identify active components, with a concomitant proposal of plausible degradation reaction mechanism for the Photo-Fenton-Like degradation into the Cu50PANI@UG composite + H2O2 + hv reaction system. Various operating parameters affecting dye degradation were evaluated, including catalyst dosage (from 0.27 to 0.67 g L−1), H2O2 concentration (from 16 to 64 mM), pH (from 3.0 to 9.0), and dye concentration (from 25 to 100 mg L−1). Optimization of key parameters such as pH, catalyst dosage, and H2O2 concentration was conducted. The highest degradation efficiency, ca. 100% of DM dye, was achieved within 35 min under optimized conditions, using Cu50PANI@UG composite as a catalytic precursor. These conditions were determined as follows: Catalyst dosage = 0.67 g L−1, pH = 3.0–6.0, H2O2 = 32–64 mM, and irradiation time of 35 min. The degradation percentage under the Response Surface Methodology (RSM) was utilized as a statistical tool to correlate influential parameters. Four consecutive reusability trials were performed to assess catalyst stability.

Three-component NiO/Fe3O4/rGO nanostructure as an electrode material towards supercapacitor and alcohol electrooxidation

A nanocomposite made of nickel oxide and iron oxide (NiO/Fe3O4) and its hybrid with reduced graphene oxide (rGO) as a conductive substrate with a highly functional surface (NiO/Fe3O4/rGO) was synthesized using a simple hydrothermal approach. This study addresses the challenge of developing efficient materials for energy storage and alcohol fuel cells. After confirming the synthesis through structural analysis, the potential of these nanocomposites as supercapacitor electrodes and catalysts for methanol and ethanol oxidation in alcohol fuel cells were evaluated. The synergy of combining the two metal oxides and adding rGO to the composite structure led to excellent electrocatalytic activity in alcohol oxidation. For the modified NiO/Fe3O4/rGO electrode in the methanol oxidation reaction (MOR), a current density of 450 mA/cm2 at 0.67 V and excellent catalyst stability of 98.7% over 20 hours in chronoamperometric analysis were observed. In the ethanol oxidation reaction (EOR), an oxidative current of 235 mA/cm2 at a peak potential of 0.76 V was seen, with catalyst stability of 96.4% after 20 hours. As a supercapacitor electrode, the NiO/Fe3O4 composite demonstrated a specific capacitance of 946 F/g, while NiO/Fe3O4/rGO showed 1155 F/g. The stability of these electrodes after 10000 GCD cycles was 83.6% and 90.6%, respectively. These findings suggest that the proposed structures are cost-effective and reliable alternatives for energy storage and production, suitable for alcohol fuel cells and supercapacitors.

Effect of Ga-Promoted on Ni/Zr + Al2O3 Catalysts for Enhanced CO2 Reforming and Process Optimization

AbstractIn this study, zirconia-modified alumina support (S) was used to investigate Ga-promoted Ni catalysts for dry reforming of methane (DRM). The catalysts (Ni + (0–3) wt% Ga/S) were prepared using the wet impregnation method and calcined at 700 °C for 3 h. The inclusion of Ga enhanced the surface area, basicity, and metal-support interaction of the Ni-Ga/S catalysts. Smaller Ni particles containing Ga were seen in the TEM. The most active and stable catalyst was Ni + 2.0 Ga/S, having a conversion of 35% CO2 and 28% CH4 at 600 °C and displaying less (17%) carbon deposition. Furthermore, the DRM process was optimized by a mathematical model. The model determined the optimal conditions as follows: temperature (800 °C), gas flow rate (GHSV—30,000 ml h−1gcat−1), and methane to carbon dioxide ratio (1:1). The model predicts CH4 and CO2 conversions of 76.76% and 82.0%, respectively, and an H2/CO ratio of 1.02, compared to experimental results showing CH4 conversion at 74.56%, CO2 conversion at 83.25%, and an H2/CO ratio of 1.01. The model demonstrates excellent agreement with the experimental observations, exhibiting less than 3% error. Graphical Abstract

Axial modulation of catalysis mechanism via charge-asymmetric for enhanced electrocatalytic performance toward hydrogen and oxygen evolution reactions

Designing efficient, stable, and nonprecious metal bifunctional catalysts is warranted for realizing the industrial application of electrocatalytic overall water splitting. Herein, we report a new catalyst (CoFe/SNC) for the HER and OER. The active site of catalysis composed of two charge-asymmetric Co/Fe atoms could axial modulation of the catalysis mechanism, thus improving the kinetics of the HER and OER. Moreover, the use of hollow porous carbon spheres as catalyst support not only enhances the distribution of Co/Fe atoms but also improves the mass transfer during the HER and OER processes. Therefore, the CoFe/SNC displays a good alkaline HER and OER activity with a small overpotential of 96.2 mV and 285.8 mV at 10 mA cm−2, respectively. Theoretical calculations reveal that the Fe atoms with optimal absorption energy for the hydrogen intermediate and the Co centers with a reduced energy barrier for the rate-determining step are the active sites for HER and OER, respectively. Additionally, the synergistic effect of Co/Fe dual-atoms could effectively optimize the intermediate adsorption of Co/Fe-N4 sites and improve the barriers of HER and OER activity and stability. This study provides valuable insight for designing bifunctional alkaline water-splitting electrocatalysts.

Plasma Induced Atomic-Scale Soldering Enhanced Efficiency and Stability of Electrocatalysts for Ampere-Level Current Density Water Splitting.

Industrial water electrolysis typically operates at high current densities, the efficiency and stability of catalysts are greatly influenced by mass transport processes and adhesion with substrates. The core scientific issues revolve around reducing transport overpotential losses and enhancing catalyst-substrate binding to ensure long-term performance. Herein, vertical Ni-Co-P is synthesized and employed plasma treatment for dual modification of its surface and interface with the substrate. The (N)Ni-Co-P/Ni3N cathode exhibits an ultra-low overpotential of 421 mV at 4000 mA cm-2, and the non-noble metal system only requires a voltage of 1.85 V to reach 1000 mA cm-2. When integrated into an anion exchange membrane (AEM) electrolyzer, it can operate stably for >300 h at 500 mA cm-2. Under natural light, the solar-driven AEM electrolyzer operates at a current density up to 1585 mA cm-2 with a solar-to-hydrogen efficiency (SHT) of 9.08%. Density functional theory (DFT) calculations reveal that plasma modification leads to an "atomic-scale soldering" effect, where the Ni3N strong coupling with the Co increases free charge density, simultaneously enhancing stability and conductivity. This research offers a promising avenue for optimizing ampere-level current density water splitting, paving the way for efficient and sustainable industrial hydrogen production.

Visualizing the structure and dynamics of transition metal-based electrocatalysts using synchrotron X-ray absorption spectroscopy.

As the global energy structure evolves and clean energy technologies advance, electrocatalysis has become a focal point as a critical conversion pathway in the new energy sector. Transitional metal electrocatalysts (TMEs) with their distinctive electronic structures and redox properties show great potential in electrocatalytic reactions. However, complex reaction mechanisms and kinetic limitations hinder the improvement of energy conversion efficiency, highlighting the necessity for comprehensive studies on structure and performance of electrocatalysts. X-ray Absorption Fine Structure (XAFS) spectra stand out as a robust tool for examining the electrocatalyst's structures and performance due to its atomic selectivity and sensitivity to local environments. This review delves into the application of XAFS technology in characterizing TMEs, providing in-depth analyses of X-ray Absorption Near-Edge Structure (XANES) spectra, and Extended XAFS (EXAFS) spectra in both R-space and k-space. These analyses reveal intrinsic structural information, electronic interactions, catalyst stability, and aggregation morphology. Furthermore, the paper examines advancements in in-situ XAFS techniques for real-time monitoring of active site changes, capturing critical intermediate and transitional states, and elucidating the evolution of active species during electrocatalytic reactions. These insights deepen our understanding on structure-activity relationship of electrocatalysts and offer valuable guidance for designing and developing highly active and stable electrocatalysts.