Recent advances in bismuth-based photocatalysts:Environment and energy applications

Photocatalysis is an effective way to solve the problems of environmental pollution and energy shortage.Numerous photocatalysts have been developed and various strategies have been proposed to improve the photocatalytic performance.Among them,Bi-based photocatalysts have become one of the most popular research topics due to their suitable band gaps,unique layered structures,and physicochemical properties.In this review,Bi-based photocatalysts(BiOX,BiVO_(4),Bi_(2)S_(3),Bi_(2)MoO_(6),and other Bi-based photocatalysts)have been summarized in the field of photocatalysis,including their applications of the removal of organic pollutants,hydrogen production,oxygen production etc.The preparation strategies on how to improve the photocatalytic performance and the possible photocatalytic mechanism are also summarized,which could supply new insights for fabricating high-efficient Bi-based photocatalysts.Finally,we summarize the current challenges and make a reasonable outlook on the future development direction of Bi-based photocatalysts.

Recent advances in Cu-based nanocomposite photocatalysts for CO_2 conversion to solar fuels

COconversion via photocatalysis is a potential solution to address global warming and energy shortage.Photocatalysis can directly utilize the inexhaustible sunlight as an energy source to catalyze the reduction of COto useful solar fuels such as CO, CH, CHOH, and CHOH. Among studied formulations, Cubased photocatalysts are the most attractive for COconversion because the Cu-based photocatalysts are low-cost and abundance comparing noble metal-based catalysts. In this literature review, a comprehensive summary of recent progress on Cu-based photocatalysts for COconversion, which includes metallic copper, copper alloy nanoparticles（NPs）, copper oxides, and copper sulfides photocatalysts, can be found. This review also included a detailed discussion on the correlations of morphology, structure, and performance for each type of Cu-based catalysts. The reaction mechanisms and possible pathways for productions of various solar fuels were analyzed, which provide insight into the nature of potential active sites for the catalysts. Finally, the current challenges and perspective future research directions were outlined, holding promise to advance Cu-based photocatalysts for COconversion with much-enhanced energy conversion efficiency and production rates.

Study of Bi_2O_3-based Rare Earth Solid Electrolyte Used in Fuel Cell

Solid ceramic electrolyte materials (Bi_2O_3)_(0.75)(Y_2O_3)_(0.25) and(Bi_2O_3)_(0.65)(Gd_2O_3 )_(0.35)were synthesized.Their crystal structure, XPS spectra and the change of ionic conductivity versus temperature were measured.A Bi_2O_3-based rare earth solid electrolyte fuel cell with ZrO_2-Y_2O_3 protection film was made.

Blended-fuel based EDC combustion model and its application in heptane-ethanol fire simulation

The blended-fuel based eddy-dissipation-concept combustion model was newly developed in the FireFOAM framework, and applied to simulate 30 cm×30 cm heptane-ethanol pool fire. Comparison was made of fire height, centerline temperature against experimental measurements, which shows that they match very well with each other. However, further studies are needed to examine the validation of this model in fire simulations with various scales.

Statistical model for combustion of high-metal magnesium-based hydro-reactive fuel

We investigate experimentally and analytically the combustion behavior of a high-metal magnesium-based hydro- reactive fuel under high temperature gaseous atmosphere. The fuel studied in this paper contains 73% magnesium powders. An experimental system is designed and experiments are carried out in both argon and water vapor atmo- spheres. It is found that the burning surface temperature of the fuel is higher in water vapor than that in argon and both of them are higher than the melting point of magnesium, which indicates the molten state of magnesium particles in the burning surface of the fuel. Based on physical considerations and experimental results, a mathematical one-dimensional model is formulated to describe the combustion behavior of the high-metal magnesium-based hydro-reactive fuel. The model enables the evaluation of the burning surface temperature, the burning rate and the flame standoff distance each as a function of chamber pressure and water vapor concentration. The results predicted by the model show that the burning rate and the surface temperature increase when the chamber pressure and the water vapor concentration increase, which are in agreement with the observed experimental trends.

Identifying the optimal HVOF spray parameters to attain minimum porosity and maximum hardness in iron based amorphous metallic coatings

Flow based Erosion e corrosion problems are very common in fluid handling equipments such as propellers, impellers, pumps in warships, submarine. Though there are many coating materials available to combat erosionecorrosion damage in the above components, iron based amorphous coatings are considered to be more effective to combat erosionecorrosion problems. High velocity oxy-fuel(HVOF)spray process is considered to be a better process to coat the iron based amorphous powders. In this investigation, iron based amorphous metallic coating was developed on 316 stainless steel substrate using HVOF spray technique. Empirical relationships were developed to predict the porosity and micro hardness of iron based amorphous coating incorporating HVOF spray parameters such as oxygen flow rate, fuel flow rate, powder feed rate, carrier gas flow rate, and spray distance. Response surface methodology(RSM) was used to identify the optimal HVOF spray parameters to attain coating with minimum porosity and maximum hardness.

Advanced Pt‐based intermetallic nanocrystals for the oxygen reduction reaction

Proton exchange membrane fuel cells(PEMFCs)are considered ideal energy‐conversion devices because of their environmentally friendly nature and high theoretical energy efficiency.However,cathodic polarization,which is a result of the sluggish oxygen reduction reaction(ORR)kinetics,is a significant source of energy loss and reduces fuel cell efficiency.Further,the need to use Pt in commercial Pt/C cathodes has restricted their large‐scale application in fuel cells because of its high cost and poor durability.Thus,improvements in the activity and durability of Pt‐based catalyst are required to reduce the amount of Pt required and,thus,costs,while increasing the ORR rate and fuel cell power density and promoting widespread PEMFC commercialization.In recent years,atomically ordered Pt‐based intermetallic nanocrystals have received tremendous attention owing to their excellent activity and stability for the ORR.Therefore,in this review,we first introduce the formation of intermetallic compounds from the perspective of thermodynamics and kinetics to lay a theoretical foundation for the design of these compounds.In addition,optimization strategies for Pt‐based ordered intermetallic catalysts are summarized in terms of the catalyst composition,size,and morphology.Finally,we conclude with a discussion of the current challenges and future prospects of Pt‐based ordered alloys.This review is designed to help readers gain insights into the recent developments in and rational design of Pt‐based intermetallic nanocrystals for the ORR and encourage research that will enable the commercialization of PEMFCs.

Model based SOC estimation for high-power Li-ion battery packs used on FCHVs

A model based method which recruited the extended Kalman filter （EKF） to estimate the full state of charge （SOC） of Li-ion battery was proposed. The underlying dynamic behavior of the cell pack was described based on an equivalent circuit comprising of two capacitors and three resistors. Measurements in two tests were applied to compare the SOC estimated by model based EKF estimation with the SOC calculated by coulomb counting. Results have shown that the proposed method is able to perform a good estimation of the SOC of battery packs. Moreover, a corresponding battery management systems （BMS） including software and hardware based on this method was designed.

Base-transesterification process for biodiesel fuel production from spent frying oils

The concept of converting recycled oils to clean biodiesel aims towards reducing the amount of waste oils to be treated and lowering the cost of biodiesel production. Samples of waste oils were prepared from Spent Frying oil collected from local hotels and restaurants in Khartoum, Sudan. Selected methods to achieve maximum yield of biodiesel using the waste feedstock were presented and compared. Some properties of the feedstock, such as free fatty acid content and moisture content, were measured and evaluated. Biodiesel yield recovery obtained, from Base-transesterification process about 92%. Produced Biodiesel specifications were also analyzed and discussed in Base-transesterification process. Kinematic viscosity of biodiesel was found to be 5.51 mm2·s?1 at 40?C, the flash point was 174.2?C and Cetane No of 48.19. Biodiesel was characterized by its physical and fuel properties according to ASTM and DIN V 51606 standards.

棉线基甲酸盐微流控燃料电池的性能测试

搭建了以棉线为流道材料的甲酸钠微流控燃料电池,利用电化学工作站测试了燃料的量、电解液的量及电极结构这三种因素对燃料电池性能的影响。结果显示:在电极结构相同的情况下,燃料的量与电解液的量均为1 mol/L时燃料电池性能较好;控制甲酸钠与氢氧化钠的量均为1mol/L,对比不同电极组合的燃料电池性能得到当阳极为石墨管电极,阴极为石墨棒电极时电池性能最佳,其最大功率密度可达85.66μW/cm^(2)。

直接甲醇燃料电池中碳基载体材料的研究进展

甲醇氧化电催化剂是决定直接甲醇燃料电池(DMFCs)性能、寿命与成本的关键。为获得高功率密度和低生产成本的DMFCs,设计合成组成、结构、形貌可控的阳极催化剂备受关注。阳极催化剂的颗粒尺寸、粒径分布、形貌结构、稳定性、分散性以及催化活性都与载体息息相关,而碳基载体材料由于其优异的性能已广泛应用于DMFCs中。首先,介绍了酸性环境和碱性环境中甲醇氧化反应的机理;然后,对不同形式的碳基载体材料,如炭黑、介孔碳、碳纳米材料、氧功能化碳、杂原子掺杂碳以及金属氧化物改性碳作为催化剂载体在DMFCs中的应用进行了综述;最后,对DMFCs的发展趋势进行了展望。

高性能机油净化碳基复合定型滤芯研制与应用

针对目前机油滤清器滤芯存在的机油净化性能差、使用寿命短等问题,通过活性炭与聚氨酯经插嵌微发泡复合定型,研发首创出具有开孔型微泡网状结构碳基复合定型滤芯,并研究其性能。结果表明,碳基复合定型滤芯属于过滤-吸附双效深层体型滤材,阻力小、流量大;通过开孔型微泡网状结构过滤作用和碳材料吸附作用的协同效应,显著提升机油净化性能、延长使用寿命;与德国马勒纸质滤清器相比,碳基复合滤清器在汽车90 km/h等速行驶测试中节约燃油达3.80%,4辆实车、累计66801公里行驶验证,碳基复合滤清器节约燃油3.17~3.33%。碳基复合滤清器节油效果显著,大规模推广与应用将产生巨大的经济效益和社会效益。

超音速火焰喷涂氧燃比对铁基非晶涂层性能的影响

非晶涂层具有优良的物理和化学性能,在工业中有广泛的应用。以FeCrMoCBSi非晶粉末为喷涂粉末,采用超音速火焰喷涂(HVOF)技术在不同喷涂参数下在Q235钢基板上沉积了铁基非晶涂层。通过X射线衍射仪(XRD)、差示扫描热仪(DSC)、扫描电子显微镜(SEM)、维氏显微硬度计等测试方法,探讨氧燃比对涂层显微组织、微观结构及耐磨性的影响。研究表明,随着喷涂氧燃比的减小,涂层的非晶相含量呈增加趋势。这是因为过量的氧气会降低喷涂过程中颗粒的熔化程度,并使颗粒氧化。涂层的显微硬度和耐磨性随氧燃比的减小而增加。这是因为在较小氧燃比下,颗粒熔化程度增加,与基板间润湿性增加,孔隙率减小。三种铁基非晶涂层相比于Q235钢基板均具有更加优良的耐磨性,有望成为碳钢表面保护和耐磨涂层的候选材料。

石墨电极棉线基微流体肼燃料电池

为找到性价比高且安全环保的供电设备,搭建以水合肼为燃料、石墨为电极以及棉线为流道材料的无催化剂微流体燃料电池(MFC),并进行性能测试。石墨管阳极、石墨棒阴极组合的MFC电化学性能最佳,电池于燃料浓度为0.075 mol/L、NaOH浓度为1.0 mol/L及电极距离为4 mm时,具有11.10μW/cm^(2)的最大功率密度和121.45μA/cm^(2)的电流密度。搭建的MFC具有材料简单、成本低且组装方便等特点,无需外部泵维持共层流,作为便携式设备具备集成化和小型化的潜力。

高参数石油基和煤基火箭煤油射线法密度测量实验研究

基于Beer-Lambert定律,采用γ射线吸收法,研制了高参数火箭煤油密度测量装置,对液态及超临界压力下火箭煤油的密度进行测量方法研究。测量温度范围293~673 K,压力范围0.3~30 MPa,密度测量结果的扩展相对不确定度为2.2%~3.2%(置信因子k=2)。选取常压、温度293 K和压力5 MPa、温度673 K的环己烷分别作为高密度和低密度标准流体,抵消了温度变化对测量装置射线吸收率的影响。通过对环己烷和甲苯密度测量的校验,验证了测量方法的可靠性和准确性。在此基础上,完成了石油基和煤基火箭煤油的密度测量,并计算了石油基和煤基火箭煤油等压热膨胀系数。利用实验数据,拟合了宽广温度压力范围内两种火箭煤油密度的Tait函数关系式,密度实验数据与方程的平均绝对偏差为0.21%,最大绝对偏差为1.32%。测量结果表明:在所测量的温度和压力范围内,煤基煤油与石油基煤油的密度值基本一致。所得密度实验测量数据为高参数火箭煤油物性及传热等研究提供了基础数据。

费托合成Co基催化剂的研究进展

Co基催化剂因具有高活性和强链增长能力等优势,成为费托合成(FTS)反应适宜的催化剂。总结了Co基催化剂FTS反应机理,并对活性相结构以及助剂与催化性能的构效关系进行了分析。同时,围绕催化剂载体的作用,总结金属-载体相互作用促进FTS反应性能的研究进展,重点分析了金属Co与分子筛耦合直接合成液体燃料的研究进展,归纳了采用双功能催化剂体系制备液体燃料的反应路线及催化剂特征。

基于OBE的燃料电池专业课程设计与实践

燃料电池课程的任务主要是使学生通过系统性学习,对燃料电池有较为全面的了解,以及掌握工作原理、电池构造、材料体系等,培养具有扎实基础且具有创新性的人才。目前,燃料电池课程的教学内容脱离行业的发展,教学方式局限于课堂教学,教学评价流于形式。引入成果导向教育(OBE)理念,对燃料电池课程的内容进行改进和实践,对效果进行科学评价与总结,以期培养复合型人才。

欧盟生物产业发展现状及趋势研究

21世纪以来,欧盟始终高度重视其生物产业的发展,既是制定生物产业相关政策及推动生物经济快速发展的先行者,也是全球生物市场最活跃的区域。对我国而言,生物产业发展起步较晚,近年来虽已取得快速发展,但与生物经济发达的国家和地区相比仍有一定差距。通过全面分析欧盟生物经济及产业发展的成功经验,对未来我国生物产业的发展提出相关建议,以期为我国生物产业发展提供决策参考。

“碳双控”形势下炼化企业的生产经营计划优化

随着我国“双碳”战略稳步推进,从能源消耗总量和强度双控(能耗双控)转向碳排放总量和强度双控(碳排放双控)的新形势对石油石化行业节能减碳提出了更高的要求。本研究从石化产业链的关键环节——炼化生产经营和计划优化的角度出发,探索炼化企业在不改变现有生产工艺和能源结构、不增加额外投资的前提下,通过优化生产方案实现碳减排的新途径。通过梳理某炼化一体化企业A和燃料型企业B的生产过程碳排放情况,创新间接排放因子计算方法,对企业每套装置的碳排放量进行精准测算,将炼油厂的碳排放量测算精度从全厂级别推进到装置级别。并进一步将装置的碳排放量纳入生产计划优化模型,研究了装置级碳排放对企业计划优化的影响,研究发现在原油加工量和乙烯产量等条件不变的情况下优化减碳空间至少3%,为A和B企业在实际生产中提供了切实可行的碳减排解决方案。

固体氧化物燃料电池Ni基阳极抗积碳的研究进展

固体氧化物燃料电池(SOFC)是一种缓解能源危机的新兴能源技术,具有效率高、可持续、无污染等优势。Ni基金属陶瓷由于兼具高电子电导、高离子电导和对碳氢燃料极佳的催化活性等优势,成为目前商业化SOFC阳极材料的最佳选择。然而,Ni基阳极SOFC在使用含碳燃料时,由于碳沉积而容易导致其失活,造成电池性能衰减。针对于此,首先,分析Ni基阳极在含碳燃料中积碳的机理,阐明Ni基阳极积碳的原因、过程、类型以及危害,并介绍探测积碳常用的表征方法;然后,归纳总结当前国内外对于改善Ni基阳极抗积碳的机制和策略;最后,对Ni基阳极抗积碳策略的发展方向提出展望。