SrCO3/SrO thermochemical energy storage is a promising technology. The sintering of strontium-based materials caused by the high temperature during SrCO3 decomposition is the major challenge for this technology. Herein, a novel method that integrates CO2 conversion and SrCO3/SrO thermochemical energy storage by using H2 to promote SrCO3 decomposition was proposed. Experimental results show that at 900 degrees C, the maximum decomposition rate of SrCO3 in the H2 atmosphere is 10 times higher than that in the N2 atmosphere. Within 600 s, the conversion of SrCO3 in the H2 atmosphere is 23 times higher than that in the N2 atmosphere. Additionally, the selectivity of CO exceeds 93 %. Density functional theory calculations reveal that the optimal reaction pathway for H2 promoted SrCO3 decomposition is the one-step decomposition of HCO3-. Electronic density difference analysis shows that H atom adsorption on CO3 2- weakens the C-O bonds, effectively decreasing the reaction energy barrier. During the H2 dissociation process, active sites of the strontium-based material could not catalyze the reaction effectively because of the physical adsorption of H2. This results in a high energy barrier of 4.65 eV for this elementary reaction, which thus becomes the rate-determining elementary reaction in the H2 promoted SrCO3 decomposition process. Compared with direct decomposition, H2 promoted SrCO3 decomposition reduces the rate-determining energy barrier by 16.1 %. Besides, SrO exhibits a self-catalytic effect on the H2 promoted SrCO3 decomposition reaction. This study provides a novel strategy for optimizing SrCO3/SrO thermochemical energy storage systems and offers a theoretical basis for further development.

Alginate, the primary polysaccharide in brown algae, comprises α-l-guluronic acid and β-d-mannuronic acid linked by β-1,4-glycosidic bonds. Its degradation is catalyzed by alginate lyases, which cleave these bonds via β-elimination to produce oligosaccharides with industrial potential. In this study, a novel PL7 alginate lyase, VaAly7A, from Vibrio alginolyticus ATCC 17749 was characterized. The mutant strain ΔVaAly7A displayed severely delayed growth on alginate and downregulated alginate-induced genes. Its two catalytic domains exhibit complementary properties: one is M-preferring (optimal at 40 °C and 1.0 M NaCl, with shorter end-products), and the other is G-preferring (optimal at 30 °C and 0.6 M NaCl, with longer end-products). Two loops around the active site are critical for the activity of each domain, with essential residues including Asn81, Pro147, His148, and Pro149 in domain one, and Thr73, Gln149, and Ala150 in domain two. These findings provide valuable enzymatic tools for the tailored production of oligosaccharides.

In the prototype testing of thermionic energy converters (TECs), in-situ monitoring of key operating parameters is of vital importance. However, owing to the complex assembly structure of TECs, direct measurement of the electrode work function and electrode gap size under high-temperature operating conditions remains challenging. In this work, we establish a mathematical model enabling the monitoring of operating parameters and demonstrate its practicality with experimental data. The simulation results reveal the dynamic changes in electrode work functions and their dependence on cathode temperature throughout the entire testing process. A more accurate estimation of the average electrode gap and displacement is achieved. After electrode activation and work function stabilization, the cathode work function decreases from 2.2 eV to 1.8 eV as the cathode temperature is reduced from 1423 K to 973 K, while the anode work function drops from 2.0 eV to 1.8 eV. Based on the Langmuir space-charge theory and Schottky effect, the influences of cathode temperature, electrode gap and work functions on the thermionic emission characteristics are also analyzed. The simulation results indicate that increasing both the electrode gap and the cathode temperature broadens the voltage range in the space-charge region. This method can directly monitor the key operating parameters of TEC prototypes from current-voltage relation, exhibiting high universality and significant direct engineering application value.

Catalytic decomposition of methane is an attractive approach for hydrogen production in a single step. To address the challenge in catalyst regeneration, a new catalytic decomposition of methane/regeneration process using iron/calcium oxide catalysts with in-situ carbon dioxide utilization for hydrogen and methanol production was proposed. First, methane is decomposed into hydrogen and solid carbon in the presence of catalysts. After mechanical separation, the solid carbon remaining in the catalyst is removed by steam gasification. Meanwhile, the produced carbon dioxide is captured by the calcium oxide in the catalyst. Finally, the conversion of carbon dioxide to methanol is achieved by in-situ carbon dioxide utilization and hydrogenation. In this work, based on the new process using iron/calcium oxide catalysts, the operation parameters for methane decomposition, carbon dioxide capture and in-situ utilization, and methanol synthesis were optimized by using Aspen Plus software. For comparison, two additional processes including the catalytic decomposition of methane/regeneration process with ex-situ carbon dioxide utilization and the catalytic decomposition of methane/regeneration process were analyzed. The energy conversion efficiency and exergy efficiency of the three processes were computed. The results show that the high temperature and low pressure are beneficial for methane decomposition. The methane conversion of 95.05% is achieved at 850 degrees C and 1 atm. The production of pure hydrogen is 33132.46 Nm3/h, and the yield of pure hydrogen is 1.48 Nm3/Nm3-methane. The energy conversion efficiency and exergy efficiency of the integrated process are are both the highest, reaching 58.74% and 50.98%, respectively. The in-situ carbon dioxide utilization reduces energy consumption, and methanol (657.11 kmol/h) synthesis using hydrogen and carbon monoxide demonstrates superior reaction performance. The net profit is 0.17 & euro;/Nm3-methane through the sale of products via the economic assessment. This work highlights promising prospects for hydrogen and methanol production via the integrated process of catalytic decomposition of methane, in-situ carbon dioxide utilization and hydrogenation.

At mid-temperature, the attractive features of the MgO/Mg(OH)2 thermochemical heat storage system include waste-free, affordable, enhanced safety control, low energy loss, and high energy density. To further enhance the heat storage performance of MgO/Mg(OH)2 by optimizing the microstructure, the hollow microtubular Fe/Zrmodified MgO was prepared by the template in this work. The effects of template type and Fe/Zr modification on cyclic heat storage capacity and reaction kinetics of MgO were studied. And mechanism of Fe/Zr codoped on the enhancement of the exothermic hydration performance of MgO was determined by density functional theory calculations. The hollow microtubular Fe/Zr-modified MgO prepared by absorbent paper template retains the high heat storage density of 1178.84 kJ/kg in 15th cycle, which is three times higher than that of MgO without template. The absorbent paper template provides MgO with the hollow microtubular structure that enhances its specific surface area. The microtubular structure and Fe enhance the hydration reaction capacity of MgO and accelerate the dehydration stage of Mg(OH)2. Meanwhile, ZrO2 improves the cyclic stability in the heat storage cycles. Fe and Zr enhance the adsorption energy of H2O on MgO by 25% and reduce the hydration energy barrier by 80.82%, which improves the heat storage capacity effectively. Therefore, the hollow microtubular Fe/ Zr-modified MgO has efficient and stable thermochemical heat storage performance.

H2 and solid carbon are available through the CH4 decomposition with Fe-based catalysts. Red mud is a solid waste containing lots of Fe2O3. In this work, the CeO2-doped solid waste-based catalyst pellets were prepared by the extrusion-spheronization method using red mud and calcium carbide slag for catalytic decomposition of CH4. The mass ratio of red mud to calcium carbide slag was 1:3. Regeneration of catalyst pellets with carbon deposits was performed by sieving separation and steam gasification. The effects of CeO2, catalyst pellet diameter, fluidization velocity, ratio and type of pore forming agent (bagasse, corn cob, horsetail pine, and walnut), ratio of binder (polyvinylpyrrolidone (PVP)), and pellet calcination duration on CH4 decomposition and regeneration of catalyst pellets were studied in a fluidized bed reactor. The electrochemical performance of the Na-ion battery using the partial solid carbon materials from CH4 decomposition as the anode materials was evaluated. The heat and mass transfer performance of catalyst pellets in fluidized state is enhanced. The initial CH4 conversion is 88% in the first catalysis/regeneration cycle at 850 degrees C with the catalyst pellet diameter of 250-425 mu m, calcination duration of 60 min, corn cob addition of 3 wt%, PVP addition of 2 wt% and fluidization velocity of 0.07 m/s. The CO2 capture by CaO in catalyst pellets during gasification boosts the residual carbon deposits removal. The reversible sodium storage capacity of the Na-ion battery using solid carbon as the carbon-based anode material is 392.0 mAh/g. The CeO2-doped solid waste-based catalyst pellets are beneficial to the H2 production, high-value utilization of solid carbon, and CO2 capture via CH4 decomposition and regeneration process.

As a major source of global greenhouse gas emissions, the cement industry is under great decarbonization pressure amid the dual-carbon goals. Conventional clinker production depends on high-temperature limestone calcination, leading to heavy fossil fuel use and massive CO2 release from carbonate decomposition. This work investigates an electrolytic limestone route powered by green electricity, which transforms calcium carbonate into cement precursor Ca(OH)2 via acid-base reactions, while co-producing hydrogen and gas mixtures. The yielded hydrogen is reused for clinker synthesis to cut carbon emissions. In this study, a systematic, full-process thermodynamic simulation of the hydrogen-fueled clinker production process based on electrolytic limestone was performed using Aspen Plus software, followed by a comprehensive comparative analysis against the traditional clinker production process. The simulation results indicate that without carbon capture, its clinker-specific carbon emission intensity reaches 664.39 kg CO2/t clinker, delivering a 31.0% direct emission reduction. It avoids the high energy penalty of conventional monoethanolamine regeneration, lowering emission intensity to 92.32 kg CO2/t clinker and achieving a total carbon reduction of 90.4%. Its overall exergy efficiency hits 44.61%, notably higher than the 31.26% of the traditional process. Economic analysis shows that the hydrogen-fueled clinker production process based on electrolytic limestone achieves the highest net present value (501.92 MUSD) and annual value (32.18 MUSD) among all carbon capture cases. Moreover, the levelized clinker cost can be reduced to approximately 70 USD/t clinker under an electricity price of 0.02 USD/kWh. This study offers theoretical and economic references for the zero-carbon transformation of the cement sector.

Abstract Chemical-looping CO2 conversion provides a promising route for sustainable CO production by separating reduction and oxidation into two steps. However, Fe-based redox materials often suffer from limited cyclic reactivity and structural degradation during repeated redox operation. In this work, Al2O3-modified Fe-based redox materials were prepared by ball milling and evaluated for chemical-looping CO2 conversion in a fixed-bed reactor. The effects of reaction temperature, support type, milling conditions, and Fe/Al molar ratio were systematically investigated. A reaction temperature of 650 °C provided nearly the maximum CO yield while avoiding unnecessary additional heat input. Ball milling alone increased the CO yield of Fe2O3 from 2.0–3.1 to 5.2–10.9 mmol g–1. Among the investigated additives, Al2O3 gave the best overall performance. The optimized FeAl-B sample with an Fe/Al molar ratio of 10:1 delivered an average CO yield of 11.82 mmol g–1 and maintained 10.24–12.21 mmol g–1 over 10 redox cycles. In comparison, ball-milled Fe without Al2O3 showed rapid deactivation. Structural characterization indicates that ball milling improves particle dispersion and Fe–Al contact, while Al2O3 helps suppress Fe coarsening and preserve the porous structure during cycling. Their combined effect improves redox reversibility and oxygen transfer. These results show that ball milling coupled with Al2O3 modification is an effective route to enhance the activity and short-term cyclic stability of Fe-based redox materials for chemical-looping CO2 conversion.

Alginate lyases are crucial for degrading alginate, a major component of brown algal cell walls, yet a large number of alginate lyases remain unclassified. This study characterizes a novel alginate lyase, VzAly7A, from Vibrio sp. B1Z05, assigned to the new PL7_7 subfamily. Biochemical analyses revealed that VzAly7A is psychrophilic (active at 4-30 °C), neutral (pH 6.0-8.0), salt-tolerant, and polyG-preferring, producing unsaturated di-, tri-, and tetrasaccharides as major end products. Domain-function studies showed that CBMs modulate activity and product profiles, and that linker 2, connecting CBM32 to the catalytic domain, is essential for alginate degradation. A conserved cysteine (Cys368) within linker 2 forms a structural disulfide bond with Cys414, which is critical for enzymatic activity. This disulfide motif appears to be unique to the PL7_7 subfamily. This work broadens the diversity known within the PL7 family and provides a promising cold-adapted biocatalyst with potential applications in food, agricultural, and biomedical industries.

Among various thermocatalytic processes, methane decomposition over Fe-based catalysts has emerged as a sustainable route for hydrogen generation, offering a zero-carbon process and valuable carbon materials. However, Fe-based catalysts still suffer from incomplete reduction of active sites, poor structural stability, and ambiguous improving mechanisms. In this work, an efficient Mo-promoted, MgAl2O4-supported Fe catalyst was developed for catalytic methane decomposition to H2 production. The methane decomposition performance of Mo/Mg/Al co-doped Fe catalysts was investigated in a fixed bed reactor. In addition, the mechanism underlying the synergistic effects of Mo, Mg, and Al on methane decomposition was elucidated. The co-doped Fe catalysts with the molar ratio of Mo : Mg : Al = 2 : 1 : 1 exhibit the highest initial methane conversion of 94.5% at 850 degrees C. This catalyst mainly consists of Fe, MgAl2O4 and MoO3. The MgAl2O4 support generated by a solid-solid reaction between MgO and Al2O3 inhibits the formation of inactive species and reinforces metal-support interactions, thereby enhancing stability. The addition of Mo further promotes the activation of Fe sites and adjusts their electronic configuration. With optimized loading, Mo significantly boosts methane conversion and hydrogen generation efficiency. The 0.8Mo-Fe2Mg4Al4 catalyst achieves an initial methane conversion of 94.5% and represents a 29.6% increase compared with the catalyst containing only Mg. Moreover, Mo stabilizes the spinel lattice, suppresses unfavorable solid solutions, and directs carbon deposition toward carbon nanotubes. Density functional theory calculation reveals that Mo enhances C-H bond activation and reduces reaction barriers, underpinning a dual effect of electronic modulation and structural stabilization. Overall, the results highlight the pivotal role of Mo in advancing Fe-based CMD catalysis and provide a foundation for the rational design of efficient hydrogen production catalysts.

The hydration/dehydration Carnot battery of calcium oxide is a promising thermal storage option for concentrating solar power plants due to its high energy density and reversibility. However, similar to 41% of solar input is released as latent heat in low-temperature steam during dehydration, which is difficult to recover and severely limits system efficiency. Here, a "steam-extraction hydration system" is proposed, in which extraction steam from the turbine is supplied directly to the hydration reactor. This design allows low-temperature steam to bypass the condenser and release its latent heat at high temperature (similar to 600 degrees C) via the hydration/dehydration chemical heat pump of calcium oxide. The approach not only improves heat recovery but also simplifies the plant configuration by avoiding complex recovery units. Thermodynamic analysis shows that conventional regenerative feedwater heating is constrained by the condensation temperature of the final extraction stage, whereas the proposed system enables an equivalent stage-free heating process. As a result, the Rankine cycle efficiency increases from 42% to 53%, and the global round-trip efficiency reaches 38% for 12 h storage. Economic analysis shows that the proposed system achieves a levelized cost of energy of 95 $/MWh, lower than that reported for conventional hydration/dehydration Carnot battery of calcium oxide. However, the net present value over a 25-year lifetime remains negative (-742 M$), indicating that further cost reductions in concentrating solar power technologies and supportive policy measures are required for large-scale deployment.

The development of efficient and stable calcium-based materials is of great importance for achieving directly solar-driven thermochemical energy storage (TCES). To address key challenges such as poor cyclic energy storage performance and low photothermal conversion of calcium-based materials, this study proposes a synergistic strategy combining microstructure regulation with the doping of multifunctional additive. Cr-doped calciumbased material with a hollow microsphere structure was synthesized by the hydrothermal method, and its cyclic TCES capacity was tested. The results indicate that Cr exists primarily in form of CaCr2O4 spinel, functioning simultaneously as the inert support, reaction promoter, and photothermal conversion agent. The hollow microsphere structure not only shortens the diffusion paths of CO2 and provides larger reaction interfaces, but also effectively buffers against pore structure degradation caused by the sintering during TCES cycles. Experimental results demonstrate that the CaCr2O4-doped hollow microsphere structured calcium-based material maintains an energy storage density of 2090 kJ/kg in the 20th cycle, which is 2.28 times that of commercial CaO. Furthermore, owing to the intrinsic light-absorbing properties of CaCr2O4 and the multi-level scattering effect of the hollow structure, CaCr2O4 -doped hollow microsphere structured calcium-based material exhibits enhanced heating rates and steady-state temperatures under simulated sunlight. Mechanistic studies based on Density functional theory calculations reveal that the spinel structure of CaCr2O4 significantly reduces the oxygen vacancy formation energy, thereby enhancing reaction activity. And CaCr2O4 effectively inhibits the sintering of calcium-based materials by anchoring CaO clusters. This study provides a novel design strategy and theoretical foundation for developing high-performance calcium-based materials for direct solar-driven TCES.

Ca(OH) 2 can be used in CO 2 uptake from the flue gas in fossil‐fired power plants. Compared with indirect method where Ca(OH) 2 is first converted into CaO and then uptakes CO 2 , direct CO 2 uptake by Ca(OH) 2 occurs at lower temperature, leading to slighter sintering. However, the direct CO 2 uptake capacity of Ca(OH) 2 should be further enhanced. In this study, Ca(OH) 2 is doped with Mn to improve its direct CO 2 uptake capacity in carbonation‐calcination‐hydration cycles. The cyclic tests are conducted in a triple fixed‐bed reactor. The mechanism of CO 2 adsorbed on Mn‐modified Ca(OH) 2 is determined by density functional theory calculations. In the first cycle, Mn‐modified sorbents acquire highest carbonation conversion at 400 °C, which is 40 °C lower than Ca(OH) 2 . The modified Ca(OH) 2 with Ca/Mn molar ratio of 100:0.75 exhibits the best performance, and its carbonation conversions reach 0.76 and 0.59 in the 1st and 20th cycles, respectively, which are 28% and 18% higher than those of Ca(OH) 2 . Furthermore, carbonation conversion of this Mn‐modified Ca(OH) 2 decreases by within 1.00% from cycle 5 to 20. Mn addition boots oxygen vacancy, increases the surface area and pore volume, and reduces the energy barrier for carbonation of Ca(OH) 2 . Mn‐modified Ca(OH) 2 as CO 2 sorbent appears promising.

The reaction characteristics of calcium-based materials during calcium looping (CaL) process are pivotal in the efficiency of CaL thermochemical energy storage (TCES) and CO2 capture systems. Currently, metal oxide doping is the primary method to enhance the reaction characteristics of calcium-based materials over multiple cycles. In particular, co-doping with variable-valence metal oxides (VVMOs) can effectively increase the oxygen vacancy content in calcium-based materials, significantly improving their cyclic reaction characteristics. However, there are so numerous VVMOs co-doping schemes that the experimental screening process is complex, consuming considerable time and economic costs. Density functional theory (DFT) calculations have been widely used to reveal the impact of metal oxide doping on the cyclic reaction characteristics of calcium-based materials, with calculation results showing good agreement with experimental conclusions. Nevertheless, there is still a lack of research on utilizing DFT to screen calcium-based materials, and a systematic research methodology has not yet been established. In this study, a systematic DFT-based screening methodology for calcium-based materials was proposed. A series of key parameters for DFT calculations including CO2 adsorption energy, oxygen vacancy formation energy, and sintering resistance were proposed. Furthermore, a preliminary mathematical model to predict the CaL TCES and CO2 capture performance of calcium-based materials was introduced. The aforementioned DFT method was employed to screen for VVMOs co-doped calcium-based materials. The results revealed that Mn and Ce co-doped calcium-based materials exhibited superior DFT-predicted reaction characteristics. These DFT predictions were validated through experimental assessments of cyclic thermochemical energy storage, CO2 capture, and relevant characterization. The outcomes demonstrate a high degree of consistency among DFT-based predictions, experimental results, and characterization. Hence, the DFT-based screening methodology for calcium-based materials proposed herein is a viable solution, poised to offer theoretical insights for the efficient design of calcium-based materials.

Brown algae are the largest-producing macroalgae, and alginate lyase plays a key role in the green degradation and high-value conversion of brown algae. This study characterized a novel alginate lyase, VSAly7C, from the marine bacterium Vibrio sp. 8-14, which belongs to the PL7_5 subfamily. Biochemical analysis suggested that VSAly7C is medium-temperature, neutral, and polyG-preferred, with enzyme activities of 2608.3 ± 27.3, 1453.2 ± 50.2, and 2545.2 ± 13.2 U/mg toward polyG, polyM, and sodium alginate, respectively. The minimal oligosaccharides VSAly7C could degrade were tetrasaccharides, and its major products were disaccharides and trisaccharides. Structural bioinformatic analysis of the VSAly7C active groove showed that the -1 to +3 subsite interaction network is crucial for determining the minimal oligosaccharides it can degrade. This study elucidates the catalytic properties, modes of action, and substrate recognition mechanisms of a novel alginate lyase, VSAly7C, which may be potentially applicable in alginate disaccharide and trisaccharide preparation.

In conventional cement production, carbonate decomposition represents the dominant contributor to CO2 emissions. Introducing green hydrogen into the calciner facilitates the reduction of limestone to CaO and CO, achieving in situ CO2 utilization while decreasing the calcination temperature, thereby resulting in mitigation of carbon emissions and energy demands. Nevertheless, this approach is limited by hydrogenation conversion efficiency of limestone. This study proposes an innovative red mud doping strategy, in which cost-effective red mud-doped limestone composites are prepared by ball milling and evaluated for hydrogenation performance in a bubbling fluidized bed reactor. Density functional theory (DFT) calculations elucidate the catalytic mechanism of Fe-4 cluster during CaCO3 hydrogenation. Results show that at 650 degrees C under 100% H-2, a red mud/limestone mass ratio of 2:20 enhances CO selectivity by 11.83% compared to natural limestone. The hydrogenation process follows a dynamic catalytic pathway, beginning with reduced Fe species as the primary active sites, which subsequently transition to calcined CaO-dominated catalysis. DFT analysis confirms that Fe active sites significantly enhance the interaction between H-2 and CaCO3 surface, reducing the H-2 dissociation barrier by 94.8% and altering the rate-limiting step. This work provides a promising approach for low-carbon cement production while simultaneously advancing sustainable red mud utilization.

The integrated calcium looping and reverse water-gas shift (CaL-RWGS) technology offers a promising approach for H2 assisted efficient CO2 conversion and utilization. Mn exhibits significant potential for enhancing the performance of the calcium-based materials in CaL-RWGS. However, the reaction mechanisms of calcium-based materials at different stages of the RWGS step, as well as the role of Mn as an additive, remain unclear. In this study, the density functional theory (DFT) calculations were employed to investigate the reaction mechanisms of pure and Mn-doped calcium-based materials during the initial and later stages of the H2 assisted CO2 conversion step. The results indicate that the dissociation of *H2 is the rate-determining reaction in all stages of the RWGS step. Compared to CaCO3, CaO provides more adsorption sites for reaction intermediates, thereby preventing the simultaneous dissociation of *H2 and decomposition of HCO3. This effect leads to a 21.3 % reduction in the reaction energy barrier. Consequently, in the later stages of the reaction, CaO exhibits self-catalytic properties for the RWGS reaction. The doping of Mn not only introduces strong chemical adsorption sites for H and OH, but also activates the reaction intermediates, thus significantly enhancing the RWGS reaction rate of the calcium-based materials. Particularly in the initial stage, Mn restructures the RWGS reaction pathway. As a result, the energy barrier for the rate-determining step on the Mn-CaCO3 is reduced by 36.8 % compared to the pure CaCO3 surface. This study provides critical insights into the CaL-RWGS process and the mechanistic role of Mn, offering valuable theoretical support for optimizing calcium-based materials and advancing CaL-RWGS technology.

Biomass-derived porous carbon (PC) has emerged as a promising candidate for electrode materials in energy storage applications, effective pretreatment of the precursor is a key strategy for enhancing the electrochemical performance of PC. However, challenges remain in achieving this goal through environmentally friendly, simple, and efficient methods. In this paper, a dual-frequency ultrasonic-assisted enzymolysis strategy combined with carbonization-activation method was proposed to prepare high-performance garlic peel-derived PC (DUGPC) for supercapacitors. Gentle and effective sonobiocatalysis facilitates microstructural regulation and composition management of the precursor, granting DUGPC an impressive specific surface area (SSA, 3006 m2/g), improved pore distribution, low metal impurity content (less than 100 ppm) and high wettability. As anticipated, DUGPC demonstrates excellent specific capacitance (408.77 F/g at 1 A/g) and rate performance (retention is 81.8 % at 50 A/g) surpassing most recently reported biomass-based PCs. In addition, the assembled aqueous symmetric supercapacitor achieves an excellent energy density of 15.78 Wh kg-1 at a power density of 50.04 W kg-1 with a remarkable cycle stability of 95.5 % after 10,000 cycles at 5 A/g, and the assembled 2.8 V high-voltage organic supercapacitor even exhibits an ultra-high energy density of 58.96 Wh kg-1 at a power density of 139.86 W kg-1. Significantly, this dual-frequency ultrasonic-assisted enzymolysis strategy is expected to be applicable to various biomass wastes and promotes the high-value utilization of biomass in the field of energy storage.

Carbon black‐loaded activated carbon (CB‐loaded AC) is a cost‐effective catalyst for CH 4 decomposition to produce H 2 . CB induces defects on the AC surface, enhancing catalytic activity. Current studies on the role of defects in promoting CH 4 decomposition are primarily experimental, with unclear mechanisms. Hence, exploring the reaction mechanism of defects in CH 4 decomposition is crucial. In this work, the Grand Canonical Monte Carlo (GCMC) and Density Functional Theory (DFT) are used to construct defects (Mono‐Vacancy defect, Di‐Vacancy defect, and Stone‐Wales defect) on the AC surface, determining the catalytic mechanism of defects in CH 4 decomposition. The results show that during the CH 4 decomposition (C─H bond cleavage) phase, defective AC reduces the energy barriers for CH 4 decomposition. Under identical conditions, the rate‐determining step of C─H bond cleavage in CH 4 occurs more readily on AC with Mono‐Vacancy, Di‐Vacancy, and Stone‐Wales defects, with corresponding reductions in energy barriers of 4.64, 2.36, and 3.12%, respectively. The total energy barriers for the reaction are reduced by 12.95, 27.58, and 8.43%, respectively. This indicates that the defects significantly lower the energy barrier for CH 4 decomposition, thereby facilitating the reaction and confirming that these defects act as active sites for the catalytic decomposition of CH 4 on AC.

Alginate, a major component of brown macroalgae, is an alternative feedstock for biorefining. The degradation of alginate oligosaccharides (AOSs) is a key prerequisite for biorefining, which usually requires at least two oligo-alginate lyases (Oals). However, the function and minimal substrate recognition mechanisms of different Oals in alginate metabolism remain poorly understood. In this study, a pair of PL17 family Oals (VaAly17A and VaAly17B) was identified, which is universal in alginate-degrading Vibrio species. VaAly17A is crucial for alginate metabolism, primarily acting on substrates larger than disaccharides, while VaAly17B contributes to rapid alginate utilization by converting disaccharides into monomers. The distinct minimal degrading substrates of the two alginate lyases are determined by a critical loop, Loop1, around the active groove. VaAly17A, with a shorter Loop1, forms an open groove for binding larger substrates, while the longer Loop1 in VaAly17B results in a shorter catalytic cleft that accommodates only smaller substrates like disaccharides. Loop swapping experiments indicate that the shorter Loop1 is crucial for interacting with larger substrates, and structure alignment suggests that this loop may serve as a hallmark to distinguish the minimal substrates among PL17 Oals. Altogether, this study, for the first time, identifies a loop of PL17 Oals determining minimal substrate recognition and provides a new strategy for distinguishing the minimal recognition patterns of PL17 Oals.