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1.
Sci Rep ; 14(1): 25312, 2024 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-39455608

RESUMO

Producing hydrogen efficiently through water electrolysis could greatly reduce fossil fuel consumption. As well as this renewable energy source will also help combat global warming and boost economic investment opportunities. This paper studied some factors affecting the performance of oxy-hydrogen/hydroxy (HHO) gas generator, such as applied voltage (from 10.5 to 13.0 V) and electrolyte solution concentration (from 0.05 to 0.20 M), using a dry fuel cell based on the electrolyzing technique of water. The results revealed that the HHO gas production rate, power consumption, and temperature change of electrolyte solution increased significantly with increasing the tested applied voltage and electrolyte concentration. This study concluded that the optimum conditions for producing HHO gas ranged from 11.5 to 12.0 V for applied voltage and from 0.05 to 0.10 M for KOH concentration according to the lowest specific energy and highest HHO gas generator efficiency. Under the previous optimum conditions, the highest productivity, specific energy, and efficiency of the HHO gas generator were 343.9 cm3 min-1, 3.43 kW h m-3, and 53.79%, respectively, using 12.0 V for applied voltage and 0.10 M for electrolyte solution concentration. These findings provide an unambiguous direction for adjusting the operational factors (applied voltage and electrolyte concentration) for efficient HHO gas production and use in different applications. Furthermore, the required energy to operate the HHO gas generator can be obtained from renewable sources.

2.
Nanomaterials (Basel) ; 14(19)2024 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-39404287

RESUMO

Climatic changes are reaching alarming levels globally, seriously impacting the environment. To address this environmental crisis and achieve carbon neutrality, transitioning to hydrogen energy is crucial. Hydrogen is a clean energy source that produces no carbon emissions, making it essential in the technological era for meeting energy needs while reducing environmental pollution. Abundant in nature as water and hydrocarbons, hydrogen must be converted into a usable form for practical applications. Various techniques are employed to generate hydrogen from water, with solar hydrogen production-using solar light to split water-standing out as a cost-effective and environmentally friendly approach. However, the widespread adoption of hydrogen energy is challenged by transportation and storage issues, as it requires compressed and liquefied gas storage tanks. Solid hydrogen storage offers a promising solution, providing an effective and low-cost method for storing and releasing hydrogen. Solar hydrogen generation by water splitting is more efficient than other methods, as it uses self-generated power. Similarly, solid storage of hydrogen is also attractive in many ways, including efficiency and cost-effectiveness. This can be achieved through chemical adsorption in materials such as hydrides and other forms. These methods seem to be costly initially, but once the materials and methods are established, they will become more attractive considering rising fuel prices, depletion of fossil fuel resources, and advancements in science and technology. Solid oxide fuel cells (SOFCs) are highly efficient for converting hydrogen into electrical energy, producing clean electricity with no emissions. If proper materials and methods are established for solar hydrogen generation and solid hydrogen storage under ambient conditions, solar light used for hydrogen generation and utilization via solid oxide fuel cells (SOFCs) will be an efficient, safe, and cost-effective technique. With the ongoing development in materials for solar hydrogen generation and solid storage techniques, this method is expected to soon become more feasible and cost-effective. This review comprehensively consolidates research on solar hydrogen generation and solid hydrogen storage, focusing on global standards such as 6.5 wt% gravimetric capacity at temperatures between -40 and 60 °C. It summarizes various materials used for efficient hydrogen generation through water splitting and solid storage, and discusses current challenges in hydrogen generation and storage. This includes material selection, and the structural and chemical modifications needed for optimal performance and potential applications.

3.
J Environ Manage ; 370: 122660, 2024 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-39332307

RESUMO

As global concern over the negative impacts of global warming, primarily caused by using passenger vehicles (PVs), the transition to hydrogen fuel cell vehicles (HFCVs) is an essential alternative for reducing greenhouse (GHG) emissions. This research employs a bottom-up approach to analyze road vehicle fleet's GHG emissions. We calculated GHG emissions from PVs in 15 Group of Twenty (G20) countries based on four scenarios adopting the global HFCVs from 2024 to 2050. This paper introduces business-as-usual (BaU), moderate, aggressive, and non-HFCVs scenario. The results show that the aggressive scenario has the highest sales, estimated between 62,000 and 29.48 million vehicles by 2050, with global hydrogen market penetration rates 48.48%. Building on countries' respective national strategies, the findings highlight China and India as the leading markets for hydrogen demand, with Germany and Japan also showing significant interest. The aggressive scenario further demonstrates that transitioning from internal combustion engine vehicles (ICEVs) to battery electric vehicles (BEVs), plug-in hybrid electric vehicles (PHEVs), and HFCVs can significantly reduce annual GHG emissions. Ultimately, this study finds that the transition to HFCVs could reduce emissions by up to 67.09% by 2050.

4.
Sensors (Basel) ; 24(17)2024 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-39275405

RESUMO

As interest in eco-friendly work vehicles grows, research on the powertrains of eco-friendly tractors has increased, including research on the development of eco-friendly vehicles (tractors) using hydrogen fuel cell power packs and batteries. However, batteries require a long time to charge and have a short operating time due to their low energy efficiency compared with hydrogen fuel cell power packs. Therefore, recent studies have focused on the development of tractors using hydrogen fuel cell power packs; however, there is a lack of research on powertrain performance analysis considering actual working conditions. To evaluate vehicle performance, an actual load measurement during agricultural operation must be conducted. The objective of this study was to conduct an efficiency analysis of powertrains according to their power source using data measured during agricultural operations. A performance evaluation with respect to efficiency was performed through comparison and an analysis with internal combustion engine tractors of the same level. The specifications of the transmission for hydrogen fuel cell and engine tractors were used in this study. The power loss and efficiency of the transmission were calculated using ISO 14179-1 equations, as shown below. Plow tillage and rotary tillage operations were conducted for data measurement. The measurement system consists of four components. The engine data load measurement was calculated using the vehicle's controller area network (CAN) data, the axle load was measured using an axle torque meter and proximity sensors, and fuel consumption was measured using the sensor installed on the fuel line. The calculated capacities, considering the engine's fuel efficiency for plow and rotary tillage operations, were 131.2 and 175.1 kWh, respectively. The capacity of the required power, considering the powertrain's efficiency for hydrogen fuel cell tractors with respect to plow and rotary tillage operations, was calculated using the efficiency of the motor, inverter, and power pack, and 51.3 and 62.9 kWh were the values obtained, respectively. Considering these factors, the engine exhibited an efficiency of about 47.9% compared with the power pack in the case of plow tillage operations, and the engine exhibited an efficiency of about 29.3% in the case of rotary tillage operations. A hydrogen fuel cell tractor is considered suitable for high-efficiency and eco-friendly vehicles because it can operate on eco-friendly power sources while providing the advantages of a motor.

5.
Materials (Basel) ; 17(15)2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-39124470

RESUMO

Optimizing the design of the top compression ring holds immense importance in reducing friction across both traditional Internal Combustion (IC) engines and hybrid power systems. This study investigates the impact of alternative fuels, specifically hydrogen and CNG, on the behavior of top piston rings within internal combustion (IC) engines. The goal of this approach is to understand the complex interplay between blow-by, fuel type, material behavior, and their effects on ring friction, energy losses, and resulting ring strength. Two types of IC engines were analyzed, taking into account flow conditions derived from in-cylinder pressures and piston geometry. Following ISO 6622-2:2013 guidelines, thick top compression rings made from varying materials (steel, cast iron, and silicon nitride) were investigated and compared. Through a quasi-static ring model within Computational Fluid Dynamics (CFD), critical tribological parameters such as the minimum film and ring friction were simulated, revealing that lighter hydrogen-powered engines with higher combustion pressures could potentially experience approximately 34.7% greater power losses compared to their heavier CNG counterparts. By delving into the interaction among the fuel delivery system, gas blow-by, and material properties, this study unveils valuable insights into the tribological and structural behavior of the top piston ring conjunction. Notably, the silicon nitride material demonstrates promising strength improvements, while the adoption of Direct Injection (DI) is associated with approximately 10.1% higher energy losses compared to PFI. Such findings carry significant implications for enhancing engine efficiency and promoting sustainable energy utilization.

6.
Proc Natl Acad Sci U S A ; 121(30): e2405846121, 2024 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-39012829

RESUMO

High-entropy compounds have been emerging as promising candidates for electrolysis, yet their controllable electrosynthesis strategy remains a formidable challenge because of the ambiguous ionic interaction and codeposition mechanism. Herein, we report a oxygenates directionally induced electrodeposition strategy to construct high-entropy materials with amorphous features, on which the structural evolution from high-entropy phosphide to oxide is confirmed by introducing vanadate, thus realizing the simultaneous optimization of composition and structure. The representative P-CoNiMnWVOx shows excellent bifunctional catalytic performance toward alkaline hydrogen evolution reaction and ethanol oxidation reaction (EOR), with small potentials of -168 mV and 1.38 V at 100 mA cm-2, respectively. In situ spectroscopy illustrates that the electrochemical reconstruction of P-CoNiMnWVOx induces abundant Co-O species as the main catalytic active species for EOR and follows the conversion pathway of the C2 product. Theoretical calculations reveal the optimized electronic structure and adsorption free energy of reaction intermediates on P-CoNiMnWVOx, thereby resulting in a facilitated kinetic process. A membrane-free electrolyzer delivers both high Faradaic efficiencies of acetate and H2 over 95% and superior stability at100 mA cm-2 during 120 h electrolysis. In addition, the unique composition and structural advantages endow P-CoNiMnWVOx with multifunctional catalytic activity and realize multipathway electrosynthesis of formate-coupled hydrogen production.

7.
Environ Sci Pollut Res Int ; 31(37): 49481-49497, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39078550

RESUMO

The pollutant emissions of diesel-powered heavy-duty trucks (HDTs) seriously damage the air quality. The promotion of hydrogen fuel cell HDTs through purchase subsidy policy to reduce emissions has become an important approach to control air pollution. This study focuses on the impact of hydrogen fuel cell HDT purchase subsidies on air quality in the context of China, covering the panel data of 31 Chinese cities from 2014 to 2021 and applying a two-way fixed effects model to analyze the contribution of purchase subsidies and hydrogen refueling station construction subsidies to air quality. Results show that (1) the increase in purchase subsidies could improve the air quality by around 6.1% and there is a lag effect. (2) Purchase subsidies make a larger contribution to air quality compared with construction subsidies. (3) Purchase subsidies can improve air quality by reducing carbon emissions in transport industry. In sight of these results, policy makers should emphasize the implementation of purchase subsidies and hydrogen refueling station construction subsidies and stimulate manufacturers to improve the performance of hydrogen fuel cell so as to contribute more to the environment.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Hidrogênio , Emissões de Veículos , Poluição do Ar/prevenção & controle , China , Poluentes Atmosféricos/análise , Veículos Automotores , Cidades
8.
Nanotechnology ; 35(47)2024 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-39079542

RESUMO

Li-ion battery is currently considered to be the most proven technology for energy storage systems when it comes to the overall combination of energy, power, cyclability and cost. However, there are continuous expectations for cost reduction in large-scale applications, especially in electric vehicles and grids, alongside growing concerns over safety, availability of natural resources for lithium, and environmental remediation. Therefore, industry and academia have consequently shifted their focus towards 'beyond Li-ion technologies'. In this respect, other non-Li-based alkali-ion/polyvalent-ion batteries, non-Li-based all solid-state batteries, fluoride-ion/ammonium-ion batteries, redox-flow batteries, sand batteries and hydrogen fuel cells etc. are becoming potential cost-effective alternatives. While there has been notable swift advancement across various materials, chemistries, architectures, and applications in this field, a comprehensive overview encompassing high-energy 'beyond Li-ion' technologies, along with considerations of commercial viability, is currently lacking. Therefore, in this review article, a rationalized approach is adopted to identify notable 'post-Li' candidates. Their pros and cons are comprehensively presented by discussing the fundamental principles in terms of material characteristics, relevant chemistries, and architectural developments that make a good high-energy 'beyond Li' storage system. Furthermore, a concise summary outlining the primary challenges of each system is provided, alongside the potential strategies being implemented to mitigate these issues. Additionally, the extent to which these strategies have positively influenced the performance of these 'post-Li' technologies is discussed.

9.
J Sep Sci ; 47(9-10): e2400088, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38801754

RESUMO

Hydrogen fuel, which is essential for the hydrogen economy, including hydrogen cell vehicles, must be of high quality for optimal hydrogen cell use. Currently, hydrogen fuel quality control is mainly done by offline analysis with periodic sampling. However, with the anticipated surge in hydrogen charging stations, there's a pressing need for cost-effective, high-throughput online analysis systems. Additionally, the miniaturization of these analytical instruments for field application is also a challenge. In this study, we present a compact, real-time hydrogen fuel analyzer based on gas chromatography with a pulsed discharge helium ionization detector. Its dual-column system efficiently analyzes major impurities in hydrogen fuel in less than 30 min. Indicator species (CO, CO2, CH4, O2, N2, and additional hydrogen sulfide [H2S]) are determined by examining hydrogen production and supply processes. The analyzer's measurement capability is consistent with µmol/mol-level analysis, providing valuable real-time information for hydrogen infrastructure managers. Additionally, it can analyze H2S, a crucial marker of sulfur compounds acting as catalytic poisons in fuel cells. This real-time analyzer offers efficient, informed decision-making support for hydrogen infrastructure managers, enhancing the overall reliability of hydrogen fuel in fuel-cell electric vehicles.

10.
J Colloid Interface Sci ; 669: 228-235, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38713961

RESUMO

The development of heterogeneous supported nanocatalysts with a high kinetics combined with low cost is off importance but remains still challenged for hydrazine hydrate served as a promising hydrogen storage material. Herein, by virtue of surficial functional groups, ultrafine NiRh NPs were monodispersed on the two-dimensional V2C surface via a conventional wet chemical co-reduction. The optimized NiRh/V2C system demonstrates an excellent catalytic performance toward selectively catalyzing dehydrogenation of hydrazine hydrate, affording 100% H2 selectivity with the turnover frequency (TOF) value of 987.5 h-1 at 323 K. Such an enhancement is mainly attributed to synergistic effect of nanosystem, which will optimize local surface energy and promote electron transfer in NiRh/V2C system, thereby improving the kinetic selectivity of catalytic hydrazine hydrate decomposition. This work has provided a facile strategy for developing nanocatalysts with high kinetics that could enable huge industrial applications in the future.

11.
Chemosphere ; 355: 141785, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38537708

RESUMO

Photoreforming is a clean photocatalytic technology for simultaneous plastic waste degradation and hydrogen fuel production, but there are still limited active and stable catalysts for this process. This work introduces the brookite polymorph of TiO2 as an active photocatalyst for photoreforming with an activity higher than anatase and rutile polymorphs for both hydrogen production and plastic degradation. Commercial brookite successfully converts polyethylene terephthalate (PET) plastic to acetic acid under light. The high activity of brookite is attributed to good charge separation, slow decay and moderate electron trap energy, which lead to a higher generation of hydrogen and hydroxyl radicals and accordingly enhanced photo-oxidation of PET plastic. These results introduce brookite as a stable and active catalyst for the photoconversion of water contaminated with microplastics to value-added organic compounds and hydrogen.


Assuntos
Ácido Acético , Plásticos , Titânio/química , Hidrogênio
12.
J Colloid Interface Sci ; 663: 971-980, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38447410

RESUMO

Electrochemical upgrading methanol into value-added formate at the anode in alkaline media enables the boosting production of hydrogen fuel at the cathode with saved energy. To achieve such a cost-effective and efficient electrocatalytic process, herein this work presents a Mn-doped nickel iron layered double hydroxides supported on nickel foam, derived from a simple hydrothermal synthesis. This developed electrocatalyst could act as an efficient bifunctional electrocatalyst for methanol-to-formate with a high faradaic efficiency of nearly 100 %, and for hydrogen evolution reaction, at an external potential of 1.5 V versus reversible hydrogen electrode. Additionally, a current density of 131.1 mA cm-2 with a decay of merely 12.2 % over 120 h continuous long-term testing was generated in co-electrocatalysis of water/methanol solution. Further density functional theoretical calculations were used to unravel the methanol-to-formate reaction mechanism arising from the doping of Fe and/or Mn. This work offers a good example of co-electrocatalysis to produce formate and green hydrogen fuel using a bifunctional electrocatalyst.

13.
Huan Jing Ke Xue ; 45(2): 744-754, 2024 Feb 08.
Artigo em Chinês | MEDLINE | ID: mdl-38471914

RESUMO

As one of the important paths for China to achieve the "dual carbon" strategy, developing hydrogen fuel cell vehicles is currently being promoted in various regions across the country, including passenger cars, coaches, and heavy-duty trucks. Quantifying the carbon reduction potential of hydrogen fuel cell vehicles for different vehicle types and regions has become a hot research topic. Using a life cycle assessment method that considers future vehicle fuel economy, power generation carbon emission factors, hydrogen production carbon emission factors, and regional differences in the scale and hydrogen production methods, this study quantitatively evaluated the life cycle carbon emissions of different types of vehicles, including fuel cell vehicles (FCV), traditional fuel vehicles (ICEV), and battery electric vehicles (BEV). We compared and analyzed the carbon reduction potential of hydrogen fuel cell vehicles at different times and in different regions and conducted an uncertainty analysis on hydrogen consumption per hundred kilometers. The results showed that by 2025, the life cycle carbon emissions of hydrogen fuel cell coaches would decrease by 36.0% compared to that of traditional fuel coaches, but the reduction in carbon emissions for hydrogen fuel cell heavy-duty trucks was not significant. By 2035, as the hydrogen energy source structure in China continues to improve, the life cycle carbon emissions of hydrogen fuel cell heavy-duty trucks were predicted to decrease by 36.5% compared to that of traditional fuel heavy-duty trucks. The decarbonization potential was most significant for heavy-duty trucks compared to that of passenger cars and coaches. Taking the Beijing-Tianjin-Hebei demonstration group as an example in 2035, as the hydrogen consumption per hundred kilometers decreases by 20%, the carbon reduction potential of FCV passenger cars, coaches, and heavy-duty trucks would increase by 7.29%, 9.93%, and 19.57%, respectively. Therefore, it is recommended to prioritize the promotion of hydrogen fuel cell coaches in the short term, heavy-duty trucks in the long term, and passenger cars as a supplement. Promoting hydrogen fuel cell vehicles in different regions and stages will help advance the low-carbon development of the automotive industry in China.

14.
Heliyon ; 10(3): e25304, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38327409

RESUMO

The urgency to mitigate greenhouse gas emissions from maritime vessels has intensified due to the increasingly stringent directives set forth by the International Maritime Organization (IMO). These directives specifically address energy efficiency enhancements and emissions reduction within the shipping industry. In this context, hydrogen is the much sought after fuel for all the global economies and its applications, for transportation and propulsion in particular, is crucial for cutting down carbon emissions. Nevertheless, the realization of hydrogen-powered vessels is confronted by substantial technical hurdles that necessitate thorough examination. This study undertakes a comprehensive analysis encompassing diverse facets, including distinct variations of hydrogen fuel cells, hydrogen internal combustion engines, safety protocols associated with energy storage, as well as the array of policies and commercialization endeavors undertaken globally for the advancement of hydrogen-propelled ships. By amalgamating insights from these multifaceted dimensions, this paper adeptly encapsulates the myriad challenges intrinsic to the evolution of hydrogen-fueled maritime vessels, while concurrently casting a forward-looking gaze on their prospective trajectory.

15.
Heliyon ; 10(2): e24181, 2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-38293461

RESUMO

This paper rigorously addresses the intricate control demands of high-speed, high-pressure, wide adjustable speed range, and high energy utilization efficiency required in hydrogen fuel cell centrifugal compressor, with a focus on the speed control of 40,000 RPM permanent magnet synchronous motors (PMSMs). An improved second-order super twisting sliding mode control (STSMC) strategy is proposed to enhance system stability and robustness by integrating the beetle antennae search (BAS) algorithm and grey wolf optimization (GWO) algorithm. The global search capability of BAS is used to improve the local optima issues of GWO, and then the improved GWO algorithm is utilized to address the issues related to parameter selection and convergence speed inherent in the STSMC. Theoretical validity of the proposed strategy is asserted through Quadratic Lyapunov Function, and its practicality is affirmed by thorough simulation. Comparative analyses are conducted with PI controller, traditional Sliding Mode Controller (SMC), and standard Super-Twisting Sliding Mode Controller (ST) under several case studies to show the superiority of the propose STSMC.

16.
ACS Appl Mater Interfaces ; 16(6): 7097-7111, 2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38296332

RESUMO

The incorporation of cerium-zinc bimetallic oxide (CeZnOx) nanostructures in sulfonated poly(2,6-dimethyl-1,4-phenylene oxide) (SPPO) membranes holds promise in an enhanced and durable fuel cell performance. This investigation delves into the durability and efficiency of SPPO membranes intercalated with CeZnOx nanostructures by varying the filler loading of 1, 2, and 3% (w/w). The successful synthesis of CeZnOx nanostructures by the alkali-aided deposition method is confirmed by wide-angle X-ray diffraction spectroscopy (WAXS), Raman spectroscopy, field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) analyses. CeZnOx@SPPO nanocomposite membranes are fabricated using a solution casting method. The intricate interplay of interfacial adhesion and coupling configuration between three-dimensional CeZnOx and sulfonic moieties of the SPPO backbone yields an enhancement in the bound water content within the proton exchange membranes (PEMs). This constructs simultaneously an extensive hydrogen bonding network intertwined with the proton transport channels, thereby elevating the proton conductivity (Km). The orchestrated reversible redox cycling involving Ce3+/Ce4+ enhances the quenching of aggressive radicals, aided by Zn2+, promoting oxygen deficiency and Ce3+ concentration. This synergistic efficacy ultimately translates into composite PEMs characterized by a mere 4% mass loss and a nominal 6% decrease in Km after rigorous exposure to Fenton's solution. Remarkably, an improved power density of 403.2 mW/cm2 and a maximum current density of 1260.6 mA/cm2 were achieved with 2% loading of CeZnOx (SPZ-2) at 75 °C and 100% RH. The fuel cell performance of SPZ-2 is 74% higher than its corresponding pristine SPPO membrane.

17.
Adv Mater ; 36(13): e2308326, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37823716

RESUMO

The air electrode is an essential component of air-demanding energy storage/conversion devices, such as zinc-air batteries (ZABs) and hydrogen fuel cells (HFCs), which determines the output power and stability of the devices. Despite atom-level modulation in catalyst design being recently achieved, the air electrodes have received much less attention, causing a stagnation in the development of air-demanding equipment. Herein, the evolution of air electrodes for ZABs and HFCs from the early stages to current requirements is reviewed. In addition, the operation mechanism and the corresponding electrocatalytic mechanisms of ZABs are summarized. In particular, by clarifying the air electrode interfaces of ZABs at different scales, several approaches to improve the air electrode in rechargeable ZABs are reviewed, including innovative electrode structures and bifunctional oxygen catalysts. Afterward, the operating mechanisms of proton-exchange-membrane fuel cells (PEMFCs) and anion-exchange-membrane fuel cells (AEMFCs) are explained. Subsequently, the strategies employed to enhance the efficiency of the membrane electrode assembly (MEA) in PEMFCs and AEMFCs, respectively, are highlighted and discussed in detail. Last, the prospects for air electrodes in ZABs and HFCs are considered by discussing the main challenges. The aim of this review is to facilitate the industrialization of ZABs and HFCs.

18.
Small Methods ; 8(3): e2301249, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38012517

RESUMO

Proton exchange membrane fuel cells (PEMFCs) are gaining significant interest as an attractive substitute for traditional fuel cells, with higher energy density, lower environmental pollution, and better operation efficiency. However, the cathode reaction, i.e., the oxygen reduction reaction (ORR), is widely proved to be inefficient, and therefore an obstacle to the widespread development of PEMFCs. The requirement for affordable highly-efficient ORR catalysts is extremely urgent to be met, especially at fuel cell level. Unfortunately, most previous reports focus on the ORR performance at rotating disk electrodes (RDE) level instead of membrane electrode assembly (MEA) level, making it harder to evaluate ORR catalysts operating under real vehicle conditions. Obviously, it is extremely necessary to develop an in-depth understanding of the structure-activity relationship of highly-efficient ORR catalysts applied at MEA level. In this work, an overview of the latest advances in ORR catalysts is provided with an emphasis on their performance at MEA level, hoping to cover the novel and systemic insights for innovative and efficient ORR catalyst design and applications in PEMFCs.

19.
ACS Appl Mater Interfaces ; 15(43): 50206-50215, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37871167

RESUMO

The conversion of lignocellulosic biomass to chemical fuel can achieve the sustainable use of lignocellulosic biomass, but it was limited by the lack of an effective conversion strategy. Here, we reported a unique approach of photothermal catalysis by using MoS2-reduced graphene oxide (MoS2/RGO) as the catalyst to convert lignocellulosic biomass into H2 fuel in alkaline solution. The RGO acting as a support for the growth of MoS2 results in the high exposed Mo edges, which act as efficient Lewis acidic sites for the oxygenolysis of lignocellulosic biomass dissolved in alkaline solution. The broad light absorption capacity and abundant Lewis acidic sites make MoS2/RGO to be efficient catalysts for photothermal catalytic H2 production from lignocellulosic biomass, and the H2 generation rate with respect to catalyst under 300 W Xe lamp irradiation in cellulose, rice straw, wheat straw, polar wood chip, bamboo, rice hull, and corncob aqueous solution achieve 223, 168, 230, 564, 390, 234, and 55 µmol·h-1·g-1, respectively. It is believed that this photothermal catalysis is a simple and "green" approach for the lignocellulosic biomass-to-H2 conversion, which would have great potential as a promising approach for solar energy-driven H2 production from lignocellulosic biomass.

20.
Sensors (Basel) ; 23(17)2023 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-37687840

RESUMO

Proton Exchange Membrane Fuel Cells (PEMFCs) are critical components in renewable hybrid systems, demanding reliable fault diagnosis to ensure optimal performance and prevent costly damages. This study presents a novel model-based fault diagnosis algorithm for commercial hydrogen fuel cells using LabView. Our research focused on power generation and storage using hydrogen fuel cells. The proposed algorithm accurately detects and isolates the most common faults in PEMFCs by combining virtual and real sensor data fusion. The fault diagnosis process began with simulating faults using a validated mathematical model and manipulating selected input signals. A statistical analysis of 12 residues from each fault resulted in a comprehensive fault matrix, capturing the unique fault signatures. The algorithm successfully identified and isolated 14 distinct faults, demonstrating its effectiveness in enhancing reliability and preventing performance deterioration or system shutdown in hydrogen fuel cell-based power generation systems.

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