燃料电池反应器在化学品与电能共生中应用

燃料电池作为能源转换装置能够高效地将化学能转化为电能,随着技术的发展人们将其作为反应器来完成高附加值的化学品的合成,同时产生一定的电能. 燃料电池反应器因具有反应条件温和、反应过程可控、产物选择性高、能源利用效率高等特点,而被广泛地应用于医药中间体的制备、气体分离、水处理等多个领域. 本文首先按照反应器中阴阳极区域发生反应的类型进行分类,介绍燃料电池反应器在化学品与电能联产中的研究现状和研究进展. 随后描述了燃料电池反应器中存在的问题,并依照催化剂、反应过程等方向对解决方案进行探讨. 最后,对几种新型燃料电池反应器的研究进行了简要的介绍并对其发展做出了展望.     

乙烷脱氢共生电能-增值化学品固体氧化物燃料电池研究进展

天然气/页岩气供应大幅增加推动了全球由乙烷制取乙烯等增值化学品的发展,深刻改变着石化产业的格局,乙烷高效清洁地转化为更高价值化学品具有深远意义. 乙烷蒸汽裂解制乙烯是一项比较成熟的工业生产技术,但是这一过程存在耗能高、积碳严重、热力学平衡受限等问题. 电能-增值化学品共生固体氧化物燃料电池由于可以将燃料气自发反应转化为高价值化学品的同时释放电能的特点被广泛研究. 本文总结了采用共生固体氧化物燃料电池将乙烷电化学脱氢共生乙烯增值化学品和电能的最新研究进展,重点介绍了固体氧化物燃料电池在乙烷脱氢中的工作原理和优势以及电解质和电极材料的选择等方向的研究发展,表明通过燃料电池技术低能耗实现乙烷共生乙烯增值化学品与电能具有显著的优越性,在实现高效节能的工业化生产中具有非常巨大的应用潜力.     

车用燃料电池系统耐久性研究北大核心CSCD

燃料电池的耐久性是燃料电池汽车的关键技术问题,车用燃料电池寿命需要达到5000小时以上才能满足汽车应用要求.作者基于车用燃料电池失效模式的研究,通过优化系统设计和改进系统控制策略等,开发出长寿命的Hy SYS-30车用燃料电池系统,并采用车用动态工况,对所开发的燃料电池系统进行了6000小时以上的耐久性测试,6000小时的性能衰减率仅为8.1%.     

质子交换膜燃料电池铂基催化剂研究进展北大核心CSCD

燃料电池是一种将化学能直接转化为电能的能量转换装置,具有能量密度高、利用率高、清洁安静等优点。在不同类型的燃料电池中,质子交换膜燃料电池(PEMFC)不仅能量密度高,而且具有在近常温条件下工作的特点,因此受到广泛关注。目前,商业化PEMFC仍采用铂基纳米材料作为催化剂,其中缺乏低成本、高效的阴极催化剂是限制PEMFC性能提升和成本降低的关键因素之一。本文综述PEMFC催化剂的结构可控制备及其对阴极氧还原反应和膜电极性能的影响,阐述调控催化剂结构提高PEMFC性能的方法,特别是提高贵金属催化剂的利用率,降低膜电极中贵金属用量的研究进展。     

CeO2/RP-PSCFM@CoFe阳极材料用于质子导体乙烷燃料电池共生乙烯和电能

The continuous consumption and excessive use of fossil fuels promote the exploration of new energy conversion technologies. Meanwhile, the increase in the supply of ethane encourages the development of industrial technology for the production of ethylene chemical raw materials. Compared with traditional fossil fuel energy conversion equipment, solid oxide ethane cogeneration fuel cells are an efficient energy processing device. Through selective oxidation of fuel gas on the anode, the endothermic process of ethane dehydrogenation is converted into an exothermic oxidation reaction, which has a greater driving force for reaction thermodynamics, and simultaneously produces clean electricity and value-added chemicals without CO₂ emissions. The anode material used for the proton conductor ethane fuel cells needs to operate stably and efficiently under hydrocarbon fuel. Consequently, excellent catalytic activity, low polarization resistance, and anti-coking stability are essential. In this work, CeO₂ was uniformly impregnated into the surface of the porous cubic perovskite Pr_0.4Sr_0.6Co_0.2Fe_0.7Mo_0.1O_3−δ anode by wet impregnation, and then calcined and reduced to obtain a CeO₂/RP-PSCFM@CoFe composite anode embedded with nanoparticles, which was successfully used in electrolyte-supported proton conductor fuel cells. CeO₂ has a high ionic conductivity and transport capacity, which accelerates the transfer rate of protons on the anode and improves the catalytic reaction and transport process. Moreover, uniformly dispersed CeO₂ can effectively increase the three-phase interface of the anode reaction and increase the range of reaction activity. The peak power densities before and after wet impregnation reached 172 and 253 mW·cm⁻², respectively, at 750 ℃. When switching to ethane as the fuel, the peak power densities reached 136 and 183 mW·cm⁻², respectively. The polarization resistance of the impregnated single cell was significantly reduced, and the catalytic activity improved. Moreover, there was no attenuation for 10 h in the long-term test. Inversely, the current density increased with the continuous reduction of the composite anode. Product analysis revealed that the yield of ethylene increased from 23.52% at 650 ℃ to 34.09% at 750 ℃, and the ethylene selectivity exceeded 94%. These results clearly show that the impregnated anode exhibited excellent catalytic activity and anti-coking ability in hydrocarbon fuels at high temperatures. Combining CoFe nanoparticles with CeO₂ enhanced the electronic conductance and ionic conductance of the electrode, improved the transmission of electric energy and the efficient conversion of chemicals, thus successfully producing the cogeneration of electric energy and ethylene.     

燃料电池膜电极衰减机制及其抗老化策略北大核心CSCD

质子交换膜燃料电池(PEMFC)具有高能量效率和高能量密度、低温快速启动、结构紧凑、无污染、低噪声等优点,在氢能汽车、固定式电站、水下潜艇和通讯电源等方面具有广泛的应用前景.目前影响燃料电池商用化的主要问题是成本和寿命,特别是在工况下急剧的启停、干湿、温度等变化,以及随之带来的机械及电化学老化,严重影响了燃料电池核心部件膜电极的耐久性和稳定性,导致燃料电池寿命大幅度下降.动态负载下燃料电池的寿命较短,距离燃料电池汽车商业化目标寿命仍有较大距离.因此,开发快速有效的膜电极加速老化测试程序,研究膜电极的耐久性,揭示燃料电池失效机理,寻找解决措施,对提高燃料电池使用寿命,推动燃料电池技术商业化,实现国民经济可持续发展具有重大意义.本文通过对比研究膜电极老化测试,从催化材料、质子交换膜以及启停控制策略应用等方面,分析电极、质子交换膜等关键材料的衰减物化机理,从材料科学领域深入探讨提升关键材料耐久性的方法及机理.为燃料电池的各部件制备与设计完善评价体系,推进燃料电池商用化发展.     

氧化还原导电水凝胶制备及其在微生物燃料电池的应用

微生物细胞与微生物燃料电池阳极之间的电子传递效率是影响产电性能的关键因素.借助阳极修饰可以促进电子转移速率,提高电池的性能.本文合成了一种以聚4-乙烯基吡啶为骨架,中性红单体为氧化还原活性中心、具有良好导电性和生物兼容性的氧化还原水凝胶材料.其中通过共价键合固定氧化还原中介体,避免了对外界环境的二次污染.以该材料修饰碳纸作为阳极组装电池,实验表明经过修饰的生物阳极驯化周期缩短,阳极电势更接近NADH/NAD的平衡电位.该电池的功率密度较未修饰的电极的电池有明显的提高.     

PtCu2八面体形貌调控及氧还原电催化性能研究北大核心CSCD

利用溶剂热法,在N,N-二甲基甲酰胺(DMF)溶剂中共同还原乙酰丙酮铂(Pt(acac)2)和乙酰丙酮铜(Cu(acac)_2)制备PtCu八面体合金催化剂.PtCu_2八面体表现出明显的晶格收缩、较高比例的非氧化态Pt单质和较高的电子结合能,进而表现出较弱的含氧物种吸附强度和较低的d带中心位置.系统研究结构导向剂对PtCu合金形貌影响.在半电池测试中,由于PtCu_2具有均匀分散的规则八面体形貌结构,导致在0.9 V vs.RHE处氧还原(ORR)的质量比活性和面积比活性分别是Pt/C(JM)的6.3和27.2倍,并在加速衰减测试后其ORR的质量比活性仍达到Pt/C(JM)的4.5倍.     

噻虫胺分子印迹电化学传感器的制备与应用EI北大核心CSCD

以噻虫胺为模板分子,通过恒电位沉积壳聚糖,在还原氧化石墨烯(RGO)修饰的玻碳电极表面制备了可特异性识别噻虫胺的分子印迹传感器。采用交流阻抗法(EIS)、差分脉冲伏安法(DPV)和循环伏安法(CV)对传感器的电化学性能进行表征,优化了电沉积时间、洗脱圈数、孵化时间及溶液pH等实验条件。在优化条件下,以K_(3)[Fe(CN)_(6)]作为电活性探针,DPV峰电流强度与噻虫胺浓度在1.0~1000 nmol/L范围内呈良好的线性关系,检出限0.46 nmol/L。将本方法应用于实际样品中噻虫胺的含量测定,加标回收率为97.6%~103.2%。     

聚合方法对聚苯胺性能的影响北大核心CSCD

分别通过苯胺的化学氧化以及N,N-二氯对苯醌二亚胺与对二溴苯格氏试剂在Ni(Ⅱ)配合物催化下共聚等两种方法合成了聚苯胺。对两种方法所获得的聚合物通过红外光谱(FT-IR)、紫外可见吸收光谱(UVVis)、循环伏安(CV)、充放电等对聚合物进行了表征和性能测试。结果表明,化学氧化法合成聚苯胺的紫外-可见吸收光谱中,在600nm处出现最大吸收峰,而金属配合物催化法合成的聚合物最大吸收峰出现在443nm。两种聚合物都具有可逆的氧化-还原性能,其氧化峰分别出现在0.26eV和0.49eV处。     

氧化铈作为阴极催化剂在直接硼氢化物燃料电池中的应用

研究以氧化铈(CeO2)作为直接硼氢化物燃料电池(DBFC)阴极催化剂的性能.结果表明:氧化铈对氧还原具有良好的催化效能,但对BH4-离子水解没有明显的促进作用,而且还能抑制它在正极的氧化.以氧化铈为阴极催化剂组装成的模拟单室燃料电池在常温下的最高功率密度为67.8mW·cm-2,运行稳定.     

固体氧化物燃料电池阳极材料研究及其在高温水电解制氢方面的应用

本文综述了固体氧化物燃料电池阳极材料的研究现状和进展。详细地介绍了国内外固体氧化物燃料电池阳极材料的制备、改性、微观结构与性能关系以及阳极反应动力学机理,并对各种材料适用的条件和优缺点进行了比较。对阳极材料在高温电解制氢领域阴极上的应用前景进行了展望。     

钨酸铋/还原氧化石墨烯二氧化氮传感器的研制EI北大核心CSCD

The bismuth tungstate / reduced graphene oxide (Bi2 WO6 / rGO) composite material was synthesized by a simple and one-step hydrothermal method, and the nitrogen dioxide gas sensor was prepared based on this material. The crystal phase, morphology and microstructure of composite were studied by XRD, Raman spectra, SEM and TEM,respectively, which confirmed that composite of Bi2 WO6 and rGO was successfully synthesized, and Bi2 WO6 / rGO composite material with flower-like superstructure was obtained. The composite material was loaded on the interdigital electrode to prepare the nitrogen dioxide gas sensor, while the properties of gas sensor were systemically investigated by using homemade gas-sensing test device. The results indicated that the Bi2 WO6 / rGO composite gas sensor had higher selectivity, higher response value and better long-term stability. The response value of Bi2 WO6 / rGO composite gas sensor was 28. 35% towards 47. 03 mg / m3 NO2, which was 3. 5 times of pure rGO gas sensor. The response time was 55 s with the recovery time of 549 s and the detection limit of 62 μg / m3. © 2022, Youke Publishing Co.,Ltd. All rights reserved.     

重量法测定含硫湿法磷酸中单质硫的含量北大核心CSCD

硫是化肥中的有益中量元素,它在土壤中能被微生物分解,通过土壤进入植物体内,是氨基酸、蛋白质和原生质等物质的组成元素,参与植物细胞内的氧化还原反应,形成具有特殊机能的谷胱甘肽、维生素B1、维生素H、异硫氰酸等,间接参与碳水化合物的代谢、叶绿素的生成,具有调节植物生长的作用,是植物生长发育必需的营养元素之一.若硫含量较低,一般会在作物生长初期显示出与缺少氮素相似的症状,降低作物吸收营养的能力,影响作物的产量[1].     

单金属位点催化剂的制备、表征及其在燃料电池中的应用

介绍了一个综合性较强的大学化学实验——单金属位点催化剂的制备及其在燃料电池中的应用。该实验是一个科研转化的综合化学实验,通过在氨气中简单热处理金属盐和氧化石墨烯,将金属原子单分散在氮掺杂的石墨烯骨架中（标记为M-NG）。通过XRD、TEM、SEM、HAADF-STEM等多种表征技术对催化材料进行结构表征,以碱性的氢氧化钾溶液为电解质测试催化剂在氧还原反应中的活性,从而开发单位点金属催化剂在燃料电池中的应用潜力。通过本实验将最前沿的学术研究成果和实践技能融入实验教学中,可以提高学生的综合实验操作技能,培养学生对科研的探究兴趣和探索能力。     

无机膜反应器在丙烷选择氧化反应中的应用

将无机膜反应器用于丙烷部分氧化制丙烯醛的反应中,考察了不同膜操作方式和反应条件的影响。实验结果表明,采用ＰＰＯＲ膜操作方式,即丙烷从渗透侧通入,氧气从反应侧通入,丙烷可获得较大的自由活化空间,避免与气相氧反应,因此提高了部分氧化反应的选择性。采用分别进样的膜反应,丙烯醛产率可比混合进样的固定床反应高出达３倍。     

Research Progress of Carbon-Encapsulated Iron-Based Nanoparticles Electrocatalysts for Zinc-Air Batteries北大核心CSCD

Zinc-air batteries (ZABs) are regarded as one of the most promising candidates for a new generation of advanced energy conversion and storage devices,while the inferior activity and stability of air cathode electrocatalysts largely hinder the widespread application of ZABs. The extensive efforts for exploring and designing high active yet stable air cathode catalysts is,therefore,indispensable for the improvement of ZABs performance. Recently,carbon-encapsulated iron-based nanoparticles have been reported to exhibit excellent oxygen catalytic performance on account of their resistance to corrosion,oxidation,and aggregation under harsh conditions,and have been widely used as cathode materials for ZABs. As a result,we systematically summarize the applications of carbon-encapsulated transition metal iron-based materials as cathode catalysts for ZABs. In this review,the basic principle of ZABs and challenges faced by air cathode catalysts are firstly expounded. Then, the research progress of the carbon-encapsulated iron-based nanoparticles electrocatalysts (such as iron-based and its alloy,carbide,oxide and phosphide,et al.) are emphatically discussed and analyzed. Finally,the future development perspectives of carbon-encapsulated iron-based electrocatalysts in the applications of ZABs are put forward. © 2022, Science Press (China). All rights reserved.     

Construction and application of an electrochemical sensor based on graphene-MXene nanocomposites for baicalin detectionEI北大核心CSCD

Redox graphene-MXene(rGO-MXene) nanocomposites were prepared by ion polymerization and used to construct a highly sensitive electrochemical sensor for baicalin(BA) detection. The synergistic effect of rGO and MXene increased the specific surface area and electron transport capacity of the electrode, and significantly enhanced the electrochemical response of BA. The cyclic voltammetry and differential pulse voltammetry were used to investigate the electrochemical behavior of BA on the sensor. Under the optimal conditions, the peak current exhibited a good linear relationship with BA concentration in the range of 0. 05-10 μmol / L, and the limit of detection was as low as 28 nmol / L. The method was applied to analyze traditional Chinese medicine preparations containing baicalin, such as Qingkailing Capsule and Sanhuang Tablets with good accuracy and spiked recovery. The results were highly consistent with those of high performance liquid chromatography, providing a technical means for the rapid and sensitive detection of traditional Chinese medicine preparations. © 2022, Youke Publishing Co.,Ltd. All rights reserved.     

碱性介质中葡萄糖在铂电极上的阳极氧化

为了进一步探明葡萄糖在铂电极上的氧化机理,用循环伏安法(CV)在-0.9～0.4 V(相对于饱和甘汞参比电极)内研究了葡萄糖在铂电极上催化氧化行为,首次详细报道了葡萄糖在电化学氧化过程中的电位振荡现象,并用电流扫描法表征了葡萄糖的电位振荡情况.电流扫描结果表明,在较慢的电流扫描速度下,电极过程出现了明显的电位振荡.说明电极上产生了毒化中间物,电位振荡是由于毒化中间物在电极上的吸附和在高电位下氧化除去引起的.     

石墨烯基杂化材料在微生物燃料电池电极中的应用

微生物燃料电池（MFC）是利用生物催化剂将污水有机物中的化学能直接转化为电能的技术,因其功率密度和能量转化效率低,电极制作成本高,限制了其大规模实际应用。因此如何提高电极的催化性能并降低电极制作成本成为MFC的研究重点方向。由于石墨烯基杂化材料具有良好的导电性和催化特性,因此石墨烯基杂化材料成为在MFC电极应用中的热点之一。本文综述了近年来MFC石墨烯基杂化电极材料的最新研究进展,重点讨论了改性石墨烯电极、金属及非金属/石墨烯杂化电极、金属氧化物/石墨烯杂化电极、聚合物/石墨烯杂化电极和石墨烯凝胶电极的设计思路和制备方法及其催化性能,着重分析了石墨烯基阳极和阴极杂化材料对MFC产电性能的影响。最后对石墨烯基杂化材料在MFC应用中存在的问题及研究前景进行了总结和展望。