Catalyst Engineering for Electrochemical Energy Conversion from Water to Water:Water Electrolysis and the Hydrogen Fuel Cell

In the context of the current serious problems related to energy demand and climate change,substantial progress has been made in developing a sustainable energy system.Electrochemical hydrogen-water conversion is an ideal energy system that can produce fuels via sustainable,fossil-free pathways.However,the energy conversion efficiency of two functioning technologies in this energy system—namely,water electrolysis and the fuel cell—still has great scope for improvement.This review analyzes the energy dissipation of water electrolysis and the fuel cell in the hydrogen-water energy system and discusses the key barriers in the hydrogen-and oxygen-involving reactions that occur on the catalyst surface.By means of the scaling relations between reactive intermediates and their apparent catalytic performance,this article summarizes the frameworks of the catalytic activity trends,providing insights into the design of highly active electrocatalysts for the involved reactions.A series of structural engineering methodologies(including nano architecture,facet engineering,polymorph engineering,amorphization,defect engineering,element doping,interface engineering,and alloying)and their applications based on catalytic performance are then introduced,w让h an emphasis on the rational guidance from previous theoretical and experimental studies.The key scientific problems in the electrochemical hydrogen-water conversion system are outlined,and future directions are proposed for developing advanced catalysts for technologies with high energy-conversion efficiency.

CO_(2) conversion to solar fuels and chemicals:Opening the new paths

This future article discusses the new prospects and directions of CO_(2)conversion via the photo-electrocatalytic(PEC)route.The second(2nd)generation solar fuels and chemicals(SFs)are generated directly in PEC systems via electrons/protons reactions without forming molecular H_(2)as an intermediate,overcoming the thermodynamics limitations and practical issues encountered for electro-fuels produced by multistep thermocatalytic processes(i.e.CO_(2)conversion with H_(2)coming from water electrolysis).A distributed and decentralized production of SFs requires very compact,highly integrated,and intensified technologies.Among the existing reactors of advanced design(based on artificial leaves or photosynthesis),the integrated photovoltaic plus electrocatalytic(PV-EC)device is the only system(demonstrated at large scale)to produce SFs with high solar-to-fuel(STF)efficiency.However,while the literature indicates STF efficiency as the main(and only)measure of process performance,we remark here the need to refer to productivity(in terms of current density)and make tests with reliable flow PEC systems(with electrodes of at least 5–10 cm^(2))to accelerate the scaling-up process.Using approaches that minimize downstream separation costs is also mandatory.Many limitations exist in PEC systems,but most can be overcome by proper electrode and cell engineering,thus going beyond the properties of the electrocatalysts.As examples of current developments,we present the progress of(i)artificial leaf/tree devices for green H_(2)distributed production and(ii)a PEC device producing the same chemicals at both cathode and anode parts without downstream operations for green solvent distributed production.Based on these developments,future directions,such as producing fertilizers and food components from the air,are outlined.The aim is to provide new ideas and research directions from a personal perspective.

Cruise/Simulink Combined Simulation for Fuel Cell Hybrid Vehicles

In order to accelerate the design of fuel cell(FC)/battery hybrid vehicles and optimize the related performance,a new modeling and simulation method for the fuel cell(FC)/battery hybrid vehicle was introduced in this paper.The co-simulation platform was set up by combining MATLAB/Simulink with AVL/Cruise,where the FC engine was realized in MATLAB/Simulink and the other most vehicle components were modeled in AVL/Cruise.The performance of a certain FC hybrid vehicle with the embedded FC engine was evaluated by using the platform.Simulation results show that this method of simulation can be applied for the design of power management strategy,power unit configuration,and performance evaluation of FC hybrid vehicles.

Process engineering in electrochemical energy devices innovation

This review focuses on the application of process engineering in electrochemical energy conversion and storage devices innovation. For polymer electrolyte based devices, it highlights that a strategic simple switch from proton exchange membranes(PEMs) to hydroxide exchange membranes(HEMs) may lead to a new-generation of affordable electrochemical energy devices including fuel cells, electrolyzers, and solar hydrogen generators. For lithium-ion batteries, a series of advancements in design and chemistry are required for electric vehicle and energy storage applications. Manufacturing process development and optimization of the LiF eP O_4/C cathode materials and several emerging novel anode materials are also discussed using the authors' work as examples.Design and manufacturing process of lithium-ion battery electrodes are introduced in detail, and modeling and optimization of large-scale lithium-ion batteries are also presented. Electrochemical energy materials and device innovations can be further prompted by better understanding of the fundamental transport phenomena involved in unit operations.

Application of Solid Oxide Fuel Cell-Auxiliary Power Unit on Different Trucks in Northeast China

A diesel engine of conventional trucks has a low efficiency under the idling condition,leading to a high cost for heating or cooling in the cab during night. The solution to this problem will have great significance on energy conservation and emission reduction. A new auxiliary power unit of solid oxide fuel cell( SOFCAPU) with high efficiency solves this problem perfectly. Heat pump air conditioner is considered as a promising device for the application of SOFC-APU with a high cooling and heating efficiency. To make a quantitative analysis for the application of SOFC-APU,a model is built in Matlab / Simulink. The diesel engine model and SOFC-APU model are fitted based on some experimental data of SOFC-APU and diesel engine during the idling operation. An analysis of the application of SOFC-APU on different trucks in Northeast China is comprehensively made,including efficiency and emission.

The Energy Optimization Mathematic Algorithm on Multi-energy Resource Powertrain of Fuel Cell Vehicle

In order to solve the core issue of the energy regulation (ER) on multi-energy resource powertrain of fuel cell vehicle, the work functions of each component were defined; the mathematical algorithm model of energy regulation was established and the relevant solution was found. This algorithm was evaluated successfully on the hardware in loop (HIL) platform under three typical urban running cycles. The results showed ER control target had been realized and the mathematical algorithm was effective and reasonable. Based on the HIL simulation, some conclusions and ER strategies were made. According to the different power component parameters and real time control request, this algorithm should be modified and calibrated for application in the actual control system.

氢能技术及其在车用领域应用现状综述

化石燃料的快速消耗迫切地需要寻找绿色清洁的替代能源,氢能是一种来源丰富、绿色低碳、应用广泛的二次能源,具有高能量、无污染的特性,是当下重要的工业原料。本文较为全面地分析了氢能的制取与储存,并且围绕氢能在车用领域的应用,因为在碳峰值和碳中和的背景下,内燃机行业的发展正面临着最好的转型机遇。加快氢发动机关键技术的研发和应用已成为世界各国政府和各大汽车企业的重要战略。本文对比了氢燃料电池与氢燃料内燃机的特点,对未来氢能源利用的产业化前景进行了分析。

浅析氢燃料电池发动机及其辅助系统状态监测与故障诊断

氢燃料电池发动机作为氢能车辆核心动力单元,其电堆运行状态健康监测和故障诊断直接影响车辆使用和电堆的寿命。当前采用的监测手段主要是对电堆电流和电堆单片电压的监控,通过判断电堆各个单体的电压一致性,以及是否有出现个别单体电压低的问题来判断电堆的健康状态。存在的问题是没有对先期机械故障即早期零部件失效进行监控,电堆能否正常工作也受制于提供空气和冷却的主要零件空压机和水泵的影响,当前仅通过电压巡检器对电堆单体电压的监测被动的报警,当报警时已经出现零件机械结构问题需要车辆进站维修更换零部件,影响车辆的正常出勤。所以有必要通过振动信号进行空压机、水泵等零部件故障的先期诊断评估,并在车辆保养或者闲时进行维修,可避免影响车辆正常营运,减少客户抱怨。

氢能源飞机的现状与未来

航空运输业碳排放较高,因此计划用氢能源代替传统航空燃油以降低碳排放,以氢燃料电池和氢燃料航空发动机作为飞机的动力源。围绕氢能源本身,对氢燃料电池和氢燃料航空燃气涡轮发动机展开论述,总结氢能源发展的主要技术难题,为氢能源飞机发展提供参考。

基于甲醇燃料的航空燃料电池内燃机混合动力系统性能分析

为了实现航空碳减排的时代需求,亟需在航空燃料体系和航空动力系统方向实现技术革新。本文提出了基于甲醇燃料的航空燃料电池内燃机混合动力系统方案,甲醇通过机载在线催化重整制氢为燃料电池供氢,燃料电池和内燃机发出的电能带动电动螺旋桨进行工作。进行了模块化建模方法和混合动力系统性能仿真分析研究,结果表明:混合动力系统的发电效率达到了55%,相比甲醇内燃机有了15%绝对值的效率提升,有助于降低燃料消耗。进行了混合动力系统性能参数影响规律分析,结果表明:混合动力系统的效率随着压比的增大而提高,随着燃料利用率的提高而呈现先升高后降低的效果。进行了混合动力系统的?分析,结果显示:混合动力系统中?效率最高的部件是燃料电池,?损最大的部件是重整器。质量分析结果表明:混合动力系统的功率密度达到0.488 kW/kg。

FCE空气过滤吸附材料压降试验与仿真研究

对于燃料电池发动机(FCE)用空气过滤器,压降大小是其主要性能参数之一。活性炭对有害气体(SO2,NOX等)有良好的吸附性能,被用于FCE空气过滤器的吸附层材料。运用实验的方法测量了空气经过活性炭颗粒堆积物的压降与空气流速,以及压降与堆积高度的关系。利用CFD软件Fluent对空气经过活性炭颗粒堆积物的压降进行了仿真研究。研究结果表明,利用压降和速度的试验数据来计算粘性阻力系数1/α和惯性阻力系数C2由此得到的仿真结果和实验结果符合良好,仿真具有可靠性。

低温燃料电池在汽车工程中的供储能特性分析

低温燃料电池作为一种先进的能源技术,其在汽车工程中的应用日益受到关注。首先,低温燃料电池技术可以直接将燃料(如氢气)的化学能转化为电能,无须经过燃烧过程,因此其能量转换效率远高于传统的内燃机。这种高效性使得低温燃料电池汽车能够在保证动力性能的同时,降低能源消耗,提高行驶里程。其次,低温燃料电池在反应过程中主要产生水和热,不产生有害的尾气和颗粒物,从而实现了零排放。此外,低温燃料电池可以使用可再生能源(如太阳能、风能等)产生的氢气作为燃料,从而实现能源的循环利用。综上,针对低温燃料电池在汽车工程中的供储能特性展开分析综述。

Strain engineering of Pt-based electrocatalysts for oxygen reaction reduction

Proton exchange membrane fuel cells(PEMFCs)are playing irreplaceable roles in the construction of the future sustainable energy system.However,the insufficient performance of platinum(Pt)-based electrocatalysts for oxygen reduction reaction(ORR)hinders the overall efficiency of PEMFCs.Engineering the surface strain of catalysts is considered an effective way to tune their electronic structures and therefore optimize catalytic behavior.In this paper,insights into strain engineering for improving Pt-based catalysts toward ORR are elaborated in detail.First,recent advances in understanding the strain effects on ORR catalysts are comprehensively discussed.Then,strain engineering methodologies for adjusting Ptbased catalysts are comprehensively discussed.Finally,further information on the various challenges and potential prospects for strain modulation of Pt-based catalysts is provided.

复合垂直流人工湿地-微生物燃料电池耦合系统产电性能和水质净化

人工湿地(CW)和微生物燃料电池技术(MFC)是两种具有潜力的环境技术,用于水污染治理和可再生能源生产。目前大部分研究主要针对上流式人工湿地-微生物燃料电池进行探索,很难用到实际的人工湿地上。主要以垂直流人工湿地为研究对象,研究复合垂直流人工湿地-微生物燃料电池耦合系统的产电性能和水质净化作用。结果表明,在相同的垂直流CW-MFC系统中,产电性能和水体污染物的含量有一定的关系;在模拟自然的水流情况下,CW-MFC1阳极生物氧化产生的质子和电子迁移至CW-MFC2的阴极也能同其电子受体发生氧化还原反应,从而产生电压电流,且其电压高于单一垂直流CW-MFC系统;模拟自然情况下的CW-MFC系统对各项水质指标的去除都有不错的去除效果,其中磷酸盐和总磷的去除率为97.5%和97.9%,氨氮和总氮的去除率为86.4%和66%,COD去除率最低为36.5%,表明复合垂直流CW-MFC系统对水体污染物的去除起明显的效果。

碳中和下商用车发展趋势

在双碳目标的背景下,交通领域节能减排成为重点关注的对象,商用车低碳化发展尤为重要,商用车将逐步形成传统能源内燃机节能增效发展,新能源商用车以纯电动及燃料电池技术为主、混合动力商用车阶段性发展,多种零碳燃料内燃机探索式发展的技术路径,支撑商用车尽早实现碳达峰。

燃料电池发动机综合性能评价工具——FCE-CPET

主要开发了一种燃料电池发动机综合性能评价软件,该软件采用C#开发语言,根据燃料电池发动机的试验数据以及已定义的评价体系,对发动机的各项指标及综合性能进行定量评价,并可对多个燃料电池发动机的性能进行对比分析.该软件提供了一个快速、直观地评价燃料电池发动机性能的工具,具有很强的实用性.

燃料电池发动机水热管理系统设计、仿真与试验验证

燃料电池水热管理系统是维持燃料电池发动机水热平衡的核心系统,其流量、温度、压力分布等都对燃料电池发动机的性能、功耗和可靠性有着重要的影响。基于某额定功率120kW的燃料电池发动机,从系统功能和性能最优的角度给出了架构方案设计、零部件选型匹配的理论依据,根据相关设计输入和设计目标要求,借助一维仿真软件FloMaster进行了水热管理系统的建模、仿真与结果分析,评估了系统在不同工况下流量、压力、温度和流速的分布,并通过台架试验手段进行了验证。仿真与试验结果表明,在系统额定工况和怠速工况点,水泵流量、电堆进出口温差、电堆入口温度等关键技术指标均满足系统目标需求。

兼容火箭推进剂的燃料电池混合能源系统

针对使用液氢/液氧的重型火箭发动机上存在氢氧蒸发气体无法有效利用的问题,提出了一种与火箭推进剂兼容的氢氧燃料电池混合能源系统设计方案。混合能源系统以满足负载使用需求为主要目标,综合考虑氢氧燃料电池效率和锂电池使用寿命,制定了混合能源系统的控制策略以及混合能源系统评价函数。基于MATLAB的仿真分析结果表明,在火箭上使用混合能源系统比单一的锂电池减重约940 kg,系统比能量提高约214.5%,且可以与箭上生命保障、环境热控系统相结合,具有广阔的实际应用前景。

无人机动力系统技术特点及选型研究

简要概述无人机的定义、分类及相关技术优势,重点对活塞式发动机、汪克尔发动机(亦称转子发动机)、喷气式发动机(含涡轮喷气发动机、涡轮风扇发动机、涡轮螺旋桨发动机、涡轮轴发动机及涡轮螺旋桨风扇发动机等)等无人机热动力系统(航空发动机),以及现阶段正在发展的燃料电池、太阳能电池及蓄电池等无人机电动力系统的技术特点进行详尽阐述,并对不同无人机动力系统的选型过程及应用可行性进行分析,为相关技术研究提供必要的理论依据。