Carbon capture is a pivotal technology for addressing CO2 emissions and promoting carbon neutrality. Porous carbons have emerged as excellent adsorbents for CO2 capture owing to their low regeneration energy consumption and economic viability. In this study, the sulfur-doped porous carbon was prepared from high-sulfur petroleum coke (PHS) via a sequential KOH-SO2 activation. The influences of sulfur functional group and pore structure on the static and dynamic CO2 adsorption performance were systematically investigated through a combination of grand canonical Monte Carlo (GCMC) simulations and experiments. GCMC results revealed that thiophenic sulfur exhibits a more pronounced enhancement effect on CO2 adsorption under low-pressure microporous conditions and demonstrates superior stability in humid environments. In contrast, oxidized sulfur species contribute to a higher isosteric heat of CO2 adsorption and improved CO2/N2 selectivity. The porosity of the samples increased significantly with the rise of the KOH activation temperature. However, treating insufficiently activated precursors with SO2 is beneficial for the further development of pores and functional groups. The optimal sample, (K3-700)-(S-600), possessing a high specific surface area (1171 m2/g) and sulfur content (14.5 wt%), delivered the maximum CO2 uptake and the highest CO2/N2 selectivity under static conditions. Sulfur doping significantly promoted CO2 adsorption at elevated temperatures and in a mixed CO2/N2/H2O atmosphere. A dynamic CO2 adsorption capacity of 0.69 mmol/g was achieved under simulated flue gas conditions (70 °C, 15% CO2, 80% N2, 5% H2O). Adsorption kinetic studies confirmed that the CO2 uptake on sulfur-doped carbons followed pseudo-second-order kinetics, suggesting the existence of multiple distinct adsorption sites and relatively high adsorption stability. This work proposes a feasible synthesis route for sulfur-doped porous carbons with promising dynamic adsorption performance, providing both theoretical insight and technical reference for CO2 capture from actual industrial flue gases.

Porous carbon has garnered significant attention as a material for CO2 adsorption due to its widely sourced, low cost, high porosity, chemical stability, rapid adsorption-desorption kinetics, and strong resistance to water. In order to enhance the interaction between carbon dioxide molecules and carbon surface, heteroatom doping is a common method to change the inherent non-polar properties of porous carbon. Among various doping strategies, sulfur doping stands out for its ability to expand interlayer spacing and modify the local electronic structure. This review comprehensively examines the mechanisms and performance of CO2 adsorption by S-doped carbon materials. It first introduces the types of S-containing functional groups and their characterization methods. Next, it summarizes the preparation approaches for S-doped porous carbon, which include endogenous sulfur-carbon co-source methods, exogenous sulfur-loading methods, and synergistic endogenous-exogenous doping strategies. Subsequently, the effects of pore structure and functional groups on CO2 adsorption performance are discussed, with insights drawn from density functional theory (DFT)，grand canonical Monte Carlo (GCMC) calculation, and experimental studies. Finally, the review explores the impact of co-doping sulfur with other elements, such as nitrogen and oxygen, on the CO2 adsorption performance. This work provides a detailed overview of the characterization, preparation, and physicochemical properties of S-doped porous carbons, alongside their influence on CO2 adsorption. It highlights the practical prospects and challenges of these materials, offering valuable insights to guide future research.

The utilization of bio-oil as a low-carbon fuel is constrained by its high oxygen content and low heating value. This study investigates the enhanced deoxygenation of bio-oil using reduced Ce/Fe-based oxygen carriers. A coupled multi-kinetic models (OFW, KAS, CR), derived from full-system thermogravimetric analysis, was employed to quantitatively elucidate the mechanisms by which Ce/Fe-based oxygen carriers promote bio-oil reforming. This approach successfully overcomes the challenge of signal overlap between oxygen donation from the oxygen carriers and bio-oil pyrolysis inherent in conventional methods. The results demonstrate that under optimal conditions (Fe/Ce molar ratio of 10:1 and bio-oil/oxygen carrier mass ratio of 10:1), a system conversion rate of 90 % was achieved alongside a relatively low activation energy. Stage mass balance analysis confirmed that the oxidation-induced weight gain of the reduced oxygen carriers occurred between 200 and 500 degrees C. Combined with multiple characterization techniques, the oxygen transfer behavior was clearly delineated. The kinetic analysis revealed that the reduced Ce/Fe-based oxygen carriers facilitated oxygen ion migration and optimized the deoxygenation pathway. This work provides a theoretical basis for the design of oxygen carrier formulations in chemical looping processes for bio-oil upgrading.

To address the self-sintering property of CaO-based materials for thermochemical energy storage and intensified deactivation of CaO-based pellets manufactured via traditional granulation process, a template-assisted granulation approach to yield highly effective morph-genetic Al-doped CaO pellets was reported here. The effects of preparation conditions on energy storage performance and mechanical properties were examined, alongside the kinetic enhancement mechanism of the hollow tubular pore structure. Results show that the morph-genetic Aldoped CaO pellets with the tableting pressure of 0.4 t and Ca/Al molar ratio of 100:10 exhibit staggered hollow tubular pores. This pore structure reduces CO2 diffusion resistance, and the generated Ca12Al14O33 stabilizes the hollow structure, thereby improving the energy storage density and cyclic stability of the pellets. The optimized pellets achieve remarkable energy storage density of 1610 kJ/kg after 50 cycles, the cumulative energy storage density of 99.23 MJ/kg and the crushing strength of 1.58 N. Even under CO2-rich calcination conditions (950 degrees C, 50 % CO2/N2 balance), their energy storage efficiency is 20 % higher than that of non-templated CaO-based pellets. The optimized pellets combine the advantages of the hierarchical porous biostructure derived from the template and improved mechanical strength, reaching a leading level in the energy storage performance of granular CaO-based pellets.

This study investigated the thermal decomposition characteristics and long-chain aliphatic hydrocarbons (C >= 7) (LCAH) preparation during catalytic co-pyrolysis of reed stems (RS) and polypropylene (PP) wastes. A TG-FTIR system and a Py-GC/MS system were employed to elucidate the characteristics of LCAH generation. Both the shift of the DTG peak from 483 to 468 degrees C and the reduction in activated energy (E-a) confirm that the co-pyrolysis technique exerted a positive effect on the decomposition of RS and PP. A higher heating rate enhanced this positive synergy. Semiquantitative analysis of FTIR absorption peaks at similar to 2960 and similar to 721 cm(-1), combined with GC/MS compositional distributions, demonstrate that the co-pyrolysis of RS and PP exhibited a synergistic effect on the LCAH generation. A reforming effect was observed between RS-derived bio-oils and PP-derived bio-oils, resulting in the production of LCAH molecules with an expanded carbon number distribution. Three possible routes were proposed to clarify the LCAH generation during co-pyrolysis of RS and PP. Temperatures of 600 to 650 degrees C and prolonged secondary reaction time were favorable for improving the yield of LCAH. In the presence of Ni-SiO2/ZrO2 catalyst, the relative content of LCAH in the bio-oils reached 62.70 area%, and the catalyst maintained excellent performance in consecutive 5 runs.

To realize the resource utilization of municipal sludge and improve the quality of gasification products, the chemical looping gasification (CLG) strategy was proposed to convert high-moisture sludge (HMS) into H2-rich syngas using a low-cost red mud-based perovskite oxygen carrier (POC), CaMn0.5Fe0.5O3-δ. H2-TPR analysis showed a high-temperature reduction peak at 651.2 °C and an H2 uptake of 3.9859 mmol/g, indicating strong reducibility and lattice oxygen mobility associated with Fe/Mn compared to conventional carriers. Under a fuel-to-oxygen-carrier ratio (C/O) of 1.75 at 800 °C in a dual-layer POC reactor, the system achieved 30.5 vol% H2 and a carbon conversion efficiency (ηC) of 90.8%, outperforming the corresponding fixed-bed configurations. Post reaction XRD and SEM-EDS analyses revealed deeper reduction of the oxygen carrier and enhanced fuel conversion, with the reduced phases such as Fe3O4 and MnFe2O4 being detected. XPS analysis further showed that the lower-layer POC contained up to 92.65% Mn2+ together with partial reduction of Fe3+ to Fe2+, supporting the active participation of lattice oxygen release and oxygen uncoupling during gas-phase reforming. These results suggest that the staged coupling strategy enhances sludge gasification and syngas upgrading through the combined effects of oxygen-carrier redox activity and improved gas-solid contact. Although the present work demonstrates the feasibility of using red mud-derived POCs for wet sewage sludge gasification, further studies are still needed on quantitative oxygen-decoupling analysis, direct tar/impurity measurement, long-term cyclic stability, and scale-up hydrodynamics.

In the process of sewage sludge (SS) fluidized pyrolysis, clarifying the evolution items of particles fragmentation is crucial to the stability and economy of the disposal way. This study systematically investigated the effects of SS moisture content (M=19.31-40.94 wt%) and pyrolysis temperature (T=600-800 degrees C) on the deformation, fragmentation, and attrition characteristics of SS particles. Quantitative high-speed photography revealed that SS particles undergo a two-stage expansion-contraction process, with the maximum contour area expansion ratio increasing from 102.4% to 108.4% as M and T rise, and the anisotropy of the deformation (radial contraction exceeding axial contraction by 2.1-9.9%) driving the generation of circular cracks. Basket sampling experiments demonstrated that the fragmentation rate is synergistically regulated by M and T: at 600 degrees C, the 30 s fragmentation rate decreases significantly from 86.4 wt% to 27.1 wt% as M increases from similar to 20% to similar to 40%, whereas at 800 degrees C, all samples approach 100% fragmentation within 60 s, a behavior attributed to the M- and T-dependent evolution of biochar pore structure and agglomeration. Cold sieving tests showed that the intrinsic particle size distribution of SS biochar shifts toward finer sizes with the increasing T, and that the fluidized attrition rate constant of SS biochar is two orders of magnitude higher than that of typical coal ash (e.g., 10(-3) vs. 10(-5) s(-1) at U=4 m/s), indicating poor wear resistance. Consequently, conventional high fluidization velocity schemes are unsuitable for SS fluidized pyrolysis systems. The quantitative data and analytical framework established in this study provide key references for the scaled design and stable operation of SS fluidized pyrolysis processes.

Owing to sluggish ion migration, structural instability, and elevated interfacial impedance, ternary lithium nickel cobalt manganese oxide (NCM) systems often fail to meet the requirements of rapid charge-discharge, resulting in low power densities in lithium-ion batteries (LIBs). This study investigates the electrochemical performance of cathodes fabricated via the integration of three types of ternary NCM material (namely NCM523, NCM811, and NCM9055) composited with activated carbon (AC) for hybrid battery supercapacitors (HBS). Attributed to the highly uniform morphology, enhanced structural stability, and high Ni percentage, NCM9055/AC composite cathodes not only a superior specific capacity (231 mAh/g at 0.1 C) but also exceptional rate charge and discharge performance and long cycling stability. At a current density of 0.5 C, the NCM9055/AC composite cathode maintained a high capacity of 222 mAh/g. Even at a high current density of 5 C, NCM9055/AC composite cathodes delivered a reversible capacity of 153 mAh/g with a retention of 79.4% after 360 cycles. Outperforming the NCM811/AC and NCM523/AC composite cathodes, demonstrating that synergistic optimization can indeed achieve the objectives of high capacity, enhanced rate capability, and improved cycling stability. Furthermore, the assembled pouch HBS, constructed with one NCM9055/AC composite cathode and two graphite anodes, achieved an energy density of 55 Wh/kg, a power density of 1,828 W/kg, and a capacity retention up to 99% after 340 cycles at 0.5 C. This indicates exceptional potential for fast charging and long cycle life, providing an innovative technical solution for application scenarios requiring high energy and rapid response.

Interactions between C–H2O(g) and C–CO2 govern the gasification efficiency and carbon reduction performance of autothermal gasifiers. In this study, a novel pulsating H2O(g) approach was proposed to enhance the reactivity of C-CO2 reaction and optimize the composition of the produced syngas. Experimental results revealed an “independence – to – competition” effect during the gasification of demineralized palm kernel shell (PKS) biochar in a conventional mixed CO2/H2O(g) atmosphere. A CO2/pulsating H2O(g) approach was developed to mitigate the competitive inhibition between C–H2O(g) and C–CO2 reactions. Carbon conversion in this novel approach was found to be highly sensitive to both the H2O(g) addition duration and the interval between consecutive H2O(g) pulses. The dependencies of syngas yield and carbon conversion on key operating parameters, including temperature, H2O(g) addition time, duration and pulse interval, were quantitatively established for the CO2/pulsating H2O(g) gasification process. Under optimal case, compared to the conventional gasification approach, the CO2/pulsating H2O(g) approach achieved a comparable syngas yield, while reaching H2O(g) consumption by 50% and producing syngas with a H2-to-CO molar ratio of 1.2 in syngas products. Life cycle assessment (LCA) results demonstrated that the CO2/pulsating H2O(g) gasification not only reduced the global warming potential (GWP) by 0.76% to 4.20%, but also achieved cost optimization (0.33% to 2.90%) across hydrogen generation, jet fuel generation, and power generation applications.

To investigate the redox performance and kinetic characteristics of iron-based oxygen carriers when mixed with iron-rich sludge ash during the sludge chemical looping gasification or combustion, the impregnation method was used to prepare Fe/Al composite oxygen carriers (Fe/Al-OC), and the iron-rich sludge ash (IRSA) was produced by high-moisture sludge burning in Muffle stove. The two types powder were then mixed in a 1:1 mass ratio to obtain another OC of Fe1Ash1. Using a thermogravimetric analyzer, the deep redox processes of the three oxygen carriers were carried out, and their reduction under variable temperature or constant temperature and oxidation processes were analyzed using 13 kinetic models to investigate their kinetic parameters. The results showed that the blending of Fe/Al-OC and IRSA exhibited a synergistic effect, in which the actual oxygen release and oxygen gain amount of Fe1Ash1 both exceed the theoretical values, indicating enhanced oxygen transport capacity. During the reduction process, under non-isothermal conditions, the oxygen release in Fe/Al-OC was controlled by two-dimensional diffusion, while the oxygen release in IRSA and Fe1Ash1 followed a first-order reaction model, with Fe1Ash1 having a slightly lower activation energy (34.81 kJ/mol) than the individual OCs. During isothermal reduction, the reaction of Fe/Al-OC transitions to contraction model control as temperature increases., IRSA maintains first-order reaction characteristics, while Fe1Ash1 reaction is more compatible with the F3/2 model, with synergistic effects weakening. During the oxidation process, Fe/Al-OC follows a first-order reaction model, while IRSA and Fe1Ash1 both follow two-dimensional diffusion models, but the activation energy of Fe1Ash1 (34.60 kJ/mol) is significantly lower than that of the other two, resulting in superior oxidation performance. Thus the Fe/Al OC might achieve complementary performance and kinetic characteristics in redox with more sludge ash blending. The highest ash blending proportion that can promote oxygen carrying capacity would be studied in next works.

Hydrogenolysis is among the most effective strategies for converting lignin into value-added chemicals, but its practical application remains hindered by low depolymerization efficiency and poor product selectivity. Microwave-assisted hydrogenolysis over appropriate catalyst emerges as a promising solution to these challenges. Metal organic frameworks (MOFs) are recognized an advanced carbon catalyst support, and catalytic activity and selectivity of the catalysts for microwave-assisted lignin hydrogenolysis are worth deep exploration, especially the intrinsic effects of the internal electronic structure changes caused by bimetallic doping. In this study, 2-phenoxy-1-phenylethanol containing abundant beta-O-4 ether bonds was selected to evaluate the behaviors of microwave-assisted lignin hydrogenolysis over a bimetallic catalyst constructed from MOFs-derived carbon. This work systematically investigated the effects of bimetallic incorporation on the internal electronic structure and the resulting activity and selectivity during the hydrogenolysis process, and the underlying mechanisms were elucidated by density functional theory (DFT) calculations. The results revealed that the internal electron redistribution induced by adjusting bimetallic doping achieved a synergistic effect between acid sites and bimetallic active sites, obtaining complete conversion of 2-phenoxy-1-phenylethanol and high phenol selectivity of 83.01%, which demonstrates enormous potential of this method in lignin and even biomass conversion.

The in situ conversion of SO2 to elemental sulfur during the regeneration process represents an advantageous approach for realizing SO2 resource utilization. In this study, the regeneration-reduction performance under a CO atmosphere was investigated using iron-loaded activated coke (Fe/AC) as adsorbent and catalyst. It was shown that for the fresh samples, the appropriate reaction temperature (450 degrees C), lower gaseous hourly space velocity (GHSV), and CO/SO2 molar ratio of 2 were conducive to the efficient conversion of SO2 to elemental sulfur. The catalytic activity initially increased and subsequently decreased over time, peaking at 7-15 h due to complete sulfidation of surface active sites. Notably, over 90 % SO2 conversion was maintained for 39.4 h. Performance decay was primarily caused by pore clogging by elemental sulfur and the covering of active site. Catalytic reduction of SO2 using regenerated Fe/AC samples showed higher performance under a CO atmosphere compared to N2 regeneration, but both were lower than fresh catalysts due to incomplete regeneration causing loss of pores and active sites. Increasing regeneration temperature and regeneration GHSV enhanced Fe/AC regeneration, improving SO2 conversion and elemental sulfur yield. Fe/AC cyclic desulfurization performance significantly decreased due to phase transformation of Fe from oxide to sulfide during regeneration-reduction. Nevertheless, both pore parameters and desulfurization performance could be restored by high-temperature water-oxygen regeneration at 450 degrees C in a 20 % H2O + 2 % O2 atmosphere. This work provides theoretical support for the resourceful and high-value recovery of SO2 from flue gas by coupling SO2 adsorbent regeneration and SO2 reduction.

For scalable high-temperature energy storage applications, Ca-based materials face the problems of sintering and poor light absorption. Recycling of nitrophosphate-making slag (NS) as Ca-based material was first reported for thermal energy storage, and the performance was further improved by dual doping strategy. Key challenges were investigated, focusing on pollutant component analysis, energy storage density at varying temperatures, cycling stability, and performance under harsh atmospheres of NS. Results show that water washing effectively reduces nitrogen content of NS, thus preventing nitrogen oxide emissions during its resource utilization. NS shows accelerated performance degradation under the calcination condition of high-concentration CO2, while the pure H2O calcination condition yields 1.9 times higher energy storage density after 10 cycles. Al-based supports minimize the sintering-induced energy storage loss of NS. Through screening five light-absorbing additives (Mn, Co, Fe, Cu and Ni), Ni/Al and Mn/Al-modified NS prepared by ion doping method demonstrates superior energy storage performance, with an optimal doping ratio of 100 (Ca as reference):4:8. The binary-dopant modified NS achieves an 800% enhancement in optical absorption and a threefold increase in energy storage density over the limestone-based benchmark following 10 cycles. The synergistic effect between CaMnO3/NiO and Ca12Al14O33 in binary-dopant modified NS significantly improves anti-sintering ability and reaction kinetics, which is evidenced by increased lattice oxygen concentration and abundant 10-100 nm pores. These findings elucidate the physicochemical properties and sintering mechanisms of nitrophosphate-making slag under energy storage conditions, and establish structure-property relationships for effective Ca-based energy storage materials.

The production of municipal sludge is increasing continuously, creating an urgent need to avoid secondary pollution from traditional disposal methods while achieving resource utilization of sludge. This study prepared Mn-modified Fe based oxygen carriers (OCs) and conducted chemical looping gasification (CLG) experiments with sludge in a fixed-bed reactor to produce high quality syngas, thereby realizing the resource utilization of sludge. The effects of reaction conditions and OC characteristics on the gasification process were investigated, and the underlying reaction mechanisms of the CLG process were elucidated using various characterization techniques. Experimental results indicate that Mn doping induces a synergistic effect between Fe and Mn elements, enhancing the reactivity of the OC. Under optimal Mn/Fe ratio conditions, the formation of the FeMnO3 component significantly improves the oxygen uncoupling capacity of the OC. At a reaction temperature of 800 degrees C and an Fe/DS ratio of 3.5, the OC achieves optimal oxygen uncoupling performance, and the released gaseous molecular oxygen leads to a high carbon conversion rate of the sludge. After oxygen uncoupling, the resulting Fe2MnO4 component exhibits low reactivity with syngas components such as CO, CH4, and H2, effectively preventing over-oxidation of the syngas and ensuring its quality. The OC utilizes the reversible "FeMnO3 <-> Fe2MnO4 + MnO + O2" oxygen uncoupling reaction and regeneration cycle to achieve efficient conversion of sludge over multiple cycles while maintaining its structural stability. This study provides valuable insights for utilizing Fe-Mn based OCs to achieve efficient sludge conversion and produce high-quality syngas.

The kinetics models for the pyrolysis of sewage sludge that are based on conventional thermogravimetric analyzers are not effective in predicting the pyrolysis behavior of sludge at higher heat-mass transfer rates. Therefore, to this end, a more robust and adaptive model is needed. In the present study, a self-designed fastreaction thermogravimetric analyzer (FR-TGA) was used to investigate the pyrolysis characteristics of sewage sludge and the influence of kinetic triplets. Based upon the results, a more accurate and reliable kinetic model was established. Results indicated that sludge pyrolysis at high heat-mass transfer rates showed lower apparent activation energy. Compared with the heating rate, the apparent kinetic parameters were more sensitive to the content of moisture in sludge. Moreover, moisture could significantly promote the pyrolysis reaction. Coupled with the mechanism of diffusion effect, a two-stage kinetic model was established, which could predict the pyrolysis process of sludge particles at high heat-mass transfer rates. The kinetic model and the behavior of various parameters could provide a reference for predicting the fast pyrolysis of sludge under different conditions.

Using SO2-rich flue gas for activating high-sulfur petroleum coke (PHS) enables collaborative utilization of industrial solid and gaseous wastes. The orthogonal experiment was designed to study the performance of SO2 in activating petroleum coke. The physicochemical properties as well as the CO2 adsorption capacity of the activated carbon prepared by the combined activation of SO2 with CO2, H2O and KOH, respectively, were also further investigated. Research shows that temperature emerges as the dominant factor governing SO2 activation efficacy, with optimal microporosity achieved at 700 degrees C and accompanied by significant sulfur enrichment dominated by thiophenic structures alongside elevated oxidized sulfur species. While both CO2 and steam promoted meso/macropore development, steam demonstrates superior performance in individual and co-activation modes due to enhanced molecular diffusivity. KOH activation produces microporous carbon with high surface area (1301 m2/g) but eliminated surface sulfur; subsequent SO2 treatment optimizes pore hierarchy by widening pores, moderately reducing surface area and micropore volume while increasing mesopore proportion and surface sulfur content. The resulting material achieves superior CO2 adsorption capacity (2.82 mmol/g) and favourable cyclic adsorption performance, establishes a cost-effective strategy for synthesizing sulfur-doped activated carbon via dual-waste utilization.

To address the recalcitrance of emerging organic micropollutants (EOMs) in wastewater, this study constructed a synergistic remediation platform coupling Chlorella pyrenoidosa with Fe2O3@SiO2@TiO2 (FST) ternary nanocomposite. Unlike conventional photocatalysis treatments limited by slow algal kinetics or narrow photocatalytic spectral responses, the synthesized core-shell FST heterojunction broadened visible-light absorption while minimizing cytotoxicity via a silica interlayer. Performance evaluations reveal that 0.125 mg/mL FST dosage significantly accelerated algal biomass accumulation, leading to superior nutrient elimination with 88.3% TN and 100% TP removal efficiencies. Crucially, the hybrid system exhibited selective removal mechanisms governed by pollutant molecular architecture, electrophilic attacked by photogenerated radicals (·OH, h+) drive near-complete mineralization of electron-rich antibiotics (SMX, TET) and endocrine disruptors (BPA, E2), whereas perfluorinated compounds (PFASs) show chain-dependent removal, achieving 100% efficiency for short-chain PFBA versus 29% for long-chain PFOA. These findings integrated biosorption, biodegradation, and photocatalytic oxidation, where microalgae function as electron sinks to suppress charge recombination, offering a sustainable paradigm for complex wastewater purification.

Polyferric coagulants are employed in municipal wastewater treatment, resulting in sludges with higher iron concentrations. In this study, iron-rich sludge ash was utilized as an oxygen carrier to systematically explore its catalytic performance in sludge gasification. The oxygen carrying performance of sludge ash was investigated by thermogravimetric analysis (TGA) and multi-cycle testing in fixed bed, the oxygen release characteristics, oxygen carrying capacity and cycling stability of sludge ash were analyzed. TG analysis showed that sludge ash had peak oxygen release capacity at 775-850 degrees C, with the highest oxygen release of 15.9 % in H2 and 5.6 % in CO initially, the oxygen-carrying capacity under syngas fell between the two values during subsequent redox cycles, and the sludge was gasified in a chemical looping gasification (CLG) way. The oxygen-carbon (O/C) ratio, significantly affected syngas quality at the beginning of the redox cycle in sludge CLG. When the initial O/C ratio was 1:10, the oxygen carrier performance of sludge ash was optimal, and the hydrogen yield was reaching 63.1 %, and syngas calorific value of 15.4 MJ/Nm3. With the increasing cycles, there was a decrease in syngas quality due to the reduction in sludge ash 's oxygen carrier performance, the sintering and pore structure degradation occurred. The optimal redox cycles with O/C ratio of 1:5, 1:10 and 1:20 were determined to be 3, 4, and 5 cycles, respectively. This study provides a theoretical foundation for sludge resource utilization and confirms the feasibility of sludge ash as a low-cost iron-based oxygen carrier in CLG technology.

Hydrogen production by green electricity electrolyzing water is a burgeoning technology inrecent years. The efficiency of hydrogen production is significantly influenced by the performance of catalysts in the electrolyzer. This research delves into the effects of the Mo and Co doping ratio, reaction parameters, and heating rate on catalyst performance. A series of systematic experiments elucidates how these variables impact the structure and electrochemical efficacy of the catalyst. The CoNiMoOx catalysts exhibited enhanced charge transfer characteristics when the Mo:Co mass ratio was 1:2, leading to improvements in electronic structure and active site distribution. Optimal preparation conditions, sunch as a 1 degrees C/min heating process to 120 degrees C over a period of 3 h, resulted in better catalyst crystallinity, stability, electrochemical activity, and longevity. Analyses utilizing scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD) confirmed a more homogeneous nanostructure and increased specific area under these optimized preparation conditions. Electrochemical evaluation further showed that the overpotential of HER was reduced by 30 % and that of OER was reduced by 15 % with the optimized catalyst. This investigation furnishes a crucial experimental foundation and theoretical underpinning for the development and synthesis of highly efficient electrocatalysts.

The presence of tip clearance not only ensures the structural safety of compression system in aero-engines,but also exerts significant negative impacts on internal flow stability due to the leakage flow.Previous studies by our team have shown that the induced shock resulting from the circumferentially diverging clearance structure has remarkable effect on suppressing leakage flow in transonic compressor rotors.Therefore,the inherent correlations between the characteristics of induced shock and leakage flow are further elucidated in this paper,and the influencing rules of induced shock wave on tip flow characteristic of transonic rotors are summarized as well.The results demonstrate that the enhancement of inhibitory effects on leakage flow and increase in the rotor's stall margin can be achieved by both intensifying the induced shock wave and shifting its circumferential position away from the suction side edge of blade tip,which is possible by adjusting the circumferential expansion ratio of diverging clearance.The stall margin of the transonic rotor exhibits three distinct variations as the circumferential expansion ratio of the diverging clearance increases monotonically,and a maximum improvement of over 8.9％can be achieved through feature variations of the induced shock wave.The insufficient acceleration of the supersonic leakage jet flow over blade tip due to a smaller circumferential expansion ratio poses challenges in inducing a shock wave,resulting in an increased blockage effect and reduced stall margin of rotor.Meanwhile,excessive circumferential expansion ratio results in a pronounced adverse pressure gradient originating from the induced shock wave,leading to leakage flow separation at the blade tip and consequently weakening the intensity of induced shock waves while shifting its circumferential position towards the blade tip.As a result,further increasing the circumferential expansion ratio does not yield an enhanced rotor stall margin but instead exhibits a slight decreasing trend.