非贵金属氧还原电极催化剂研究进展

质子交换膜燃料电池(PEMFC)中普遍使用Pt作为阴极电催化剂,但由于Pt价格昂贵、储量稀少,PEMFC中使用大量的Pt,必然导致PEMFC制造成本的上升。因此,寻找一种能够部分或者完全达到Pt催化效果的非贵金属催化剂,成为一种可行的方法。本文对近年来非贵金属氧还原电极催化剂的研究进行了总结,特别是不同催化剂的制备方法、反应机理及活性中心进行了梳理,并对非贵金属氧还原电极催化剂的发展进行了展望。     

燃料电池阴极氧还原电极材料研究进展

目前燃料电池阴极氧还原电极材料主要以铂基贵金属电催化剂为主,然而铂的储量极其有限,成本昂贵,并且铂基电催化剂的稳定性较差,这些因素严重制约了其在商业中的广泛应用,因此研究制备成本低、具有高稳定性的非贵金属碳基催化剂是燃料电池电催化剂的研究重点。本文简单概述了燃料电池阴极氧还原电极材料的研究进展。     

多孔碳基非贵金属氧还原电催化剂研究进展

氧还原反应电催化剂在能量储存和转换中的应用受到了广泛关注，铂基贵金属催化剂因成本高、资源稀缺等缺点限制了其规模化应用。碳基非贵金属催化剂因价格低廉、反应活性好和抗甲醇渗透能力强等优点有望成为铂基催化剂的替代品。目前，文献报道的碳基催化剂主要通过调控活性位点的电子结构、增加活性位点密度与可接近性及调控碳/金属复合材料界面结构等策略提升其氧还原活性。从非金属元素掺杂碳基催化剂、碳基非贵金属单原子催化剂和碳基非贵金属纳米颗粒催化剂3个方面综述了碳基氧还原催化剂的研究进展，总结和指出了碳基催化剂面临的问题及挑战，并对催化剂的发展前景进行了展望。     

氮掺杂非贵金属氧还原催化剂研究进展

综述了近几年来用于直接甲醇燃料电池阴极氧还原反应的含氮碳催化材料发展状况,包括催化剂制备过程中热处理条件、金属的种类及负载量、碳载体、新型合成方法等影响催化剂氧还原活性的几个因素。针对当前研究工作的局限展开了评论,指出催化机理和优化制备过程是氮掺杂碳材料负载非贵金属氧还原催化剂深入研究的重点和主要方向。     

低温CO催化氧化复合型非贵金属催化剂的研究进展

综述了复合型非贵金属催化剂在低温CO催化氧化反应中的研究进展,着重介绍了ABO3钙钛矿型负载氧化物、非钙钛矿型负载氧化物和尖晶石型氧化物这两类复合型非贵金属催化剂的制备方法及其催化性能,并对今后低温CO催化氧化非贵金属催化剂的研究方向作了展望。     

质子交换膜燃料电池非铂电催化剂研究进展

质子交换膜燃料电池(PEMFCs)目前主要催化剂为贵金属Pt基催化剂。然而,Pt价格高、储量低等问题严重阻碍了PEMFCs的商业化进程。发展低成本、高性能的氧还原催化剂是解决铂资源短缺、降低燃料电池成本、实现燃料电池商业化的关键。结合本课题组的研究工作,综述了最近几年非铂催化剂在燃料电池阴极氧还原方面的研究进展,着重探讨了新型氮掺杂碳基纳米材料的设计与制备,并概述了非铂催化剂面临的困难以及未来发展方向。     

燃料电池中铁基氧还原催化剂的研究进展

阴极氧还原反应是燃料电池的核心反应之一。目前催化氧还原反应的催化剂通常是贵金属铂,但其普遍存在成本高、对甲醇耐受性差、易CO中毒等缺点,因此开展非贵金属催化剂的研究显得尤为重要。铁基催化剂因催化活性好、稳定性高、甲醇耐受性好、价格低廉等备受青睐,最有希望成为铂基催化剂的替代品。本文主要综述了几类铁基氧还原催化剂的研究现状、催化机理及活性影响因素,并在此基础上阐述了各类催化剂目前尚待解决的问题和发展方向。     

青岛能源所在石墨炔作为催化剂应用研究中取得进展

正氧还原反应作为燃料电池和金属—空气电池中的重要反应过程,受到广泛关注。传统的氧还原反应催化剂为铂基催化剂,铂价格昂贵,其成本超过燃料电池堆总成本的55%。近年来,科研人员制备了一系列的非贵金属催化剂,替代贵金属铂。其中,碳基催化剂因具有低成本、高稳定性、储量丰富,以及较强的抗一氧化碳和甲醇性能,获得关注。近日,中国科学院青岛生物能源与过程研究所新型能源碳素材料团队研发了一种氮掺杂的石墨炔材料,用作氧还原反应,表现出优异的催化性能。     

非贵金属催化剂催化制备对氨基苯酚研究进展

综述了对硝基苯酚催化还原制备对氨基苯酚所用催化剂的研究进展,高活性的贵金属催化剂由于高成本和稀缺性限制了它们大规模的实际应用,故非贵金属可作为催化对硝基苯酚制备对氨基苯酚反应催化剂的研究重点。     

负载型贵金属低温催化氧化甲醛催化剂的研究

制备贵金属低温催化氧化甲醛催化剂,研究了催化剂结构特征及催化氧化甲醛机理,并考察了催化剂性能。采用沉积-沉淀法制备负载型贵金属低温催化氧化甲醛催化剂,优化组成及制备条件,采用XRD、FT-IR、H_2-TPR、拉曼等对催化剂进行表征分析。催化剂最佳制备条件:NaOH为沉淀剂,载体n(Cu)/n(Mn)摩尔比为1∶2,Pt负载量(质量分数)为1%,载体制备pH为9—10,贵金属负载pH为9.5。Pt_1/Cu_(0.5)Mn催化剂以非化学计量比Cu_(0.9)Mn_(1.8)O_4无定形态晶体特征峰存在,Pt金属在载体表面分布均匀,且贵金属与载体相互作用使催化剂表面氧缺位浓度增加,表面活性氧物种增多,催化剂在室温下表现出良好的稳定性和重复性。室温下甲醛和氧气在催化剂表面共吸附,甲醛首先被催化剂表面活性氧氧化为DOM,由于DOM很活跃,在催化剂上很快被表面氧氧化成甲酸根,甲酸根在催化剂表面氧和气相氧的共同作用下氧化生成CO,最终被完全氧化为CO_2。其中甲酸盐物种向CO转化步骤是整个反应的速控步骤。     

金属大环化合物基氧还原电催化剂的研究进展

作为燃料电池的关键反应,阴极电极上的氧还原反应（ORR）的反应动力学缓慢,需要大量昂贵的铂基电催化剂提高反应动力学。然而,铂的价格昂贵、稀缺和耐久性差等问题严重阻碍了燃料电池系统在实际中的广泛应用。因此,发展廉价高活性的非贵金属氧还原反应催化剂是实现燃料电池商业应用关键途径之一。大环化合物基催化剂以其独特的配位结构和高共轭化学性质发展迅速,被认为是铂基材料的潜在替代品。本文总结了近年来金属大环化合物基氧还原催化剂的发展和研究成果,着重探讨了金属大环化合物基氧还原催化剂的设计和制备,并概述了金属大环化合物基氧还原催化剂面临的挑战和未来的发展方向。     

电催化氧气析出非贵金属催化剂的研究进展

电催化氧气析出反应是金属-空气电池充电过程和电催化分解水阳极的关键反应,对提高能量储存和转换效率、高效利用可再生清洁能源、缓解能源危机和环境污染具有重要作用。文章首先简要介绍了电催化氧气析出反应基本过程,随后综述了近年来用于电催化氧气析出反应的非贵金属催化剂的研究进展,重点讨论了过渡金属氧化物、过渡金属氢氧化物以及碳材料等非贵金属催化剂的研发情况。对这些催化剂的合成、结构及氧气析出催化性能进行了详细分析,也对这些催化剂的发展方向进行了简单分析。文章最后认为,新合成技术、新催化材料的发展以及氧气析出催化反应机理的阐明对发展高性能电催化氧气析出非贵金属催化剂将会起到极大的推动作用。     

移动源中消除NO_x的催化剂

本文分析了在移动源中消除NOx的几种催化剂，包括贵金属催化剂、贱金属催化剂、稀土复合氧化物催化剂，并对其作了展望。     

Synthesis of nitrogen-doped onion-like carbon and its use in carbon-based CoFe binary non-precious-metal catalysts for oxygen-reduction

Nitrogen-doped onion-like carbon-rich materials were synthesized by heat treatment of a “hybrid” containing hexamethylene diamine complex in the presence of Co and Fe species while preparing non-precious metal electrocatalyst for oxygen-reduction. As demonstrated by electrochemical rotating disk electrode and fuel cell tests, the binary CoFe-based catalyst containing graphitized onion-like carbon nanostructures provides for improved performance relative to the single Fe-based catalyst in which no such carbon structure was observed. In the binary catalysts, variation of the ratios of Co to Fe and the total metal loading during the synthesis leads to a markedly different activity and four-electron selectivity for oxygen reduction. The optimized binary catalyst was studied in fuel cell lifetime tests using both constant current and voltage models, showing a good combination of activity and durability. Possible reasons for the improved performance of the CoFe-based binary catalyst are discussed. The graphitized onion-like carbon structure exclusively derived from Co in this work may be providing a robust matrix to host non-precious metal active sites, which would prevent water flooding of them, and increase the resistance to oxidative attack in the oxygen cathode, thereby leading to an improvement in performance durability.     

Comparison of the reaction mechanisms of electrocatalytic oxygen reduction using transition metal thiospinels and chelates

The cathode process of oxygen reduction on thiospinels and other sulphides was examined by potentiodynamic, galvanostatic and rotating ring-disc electrode measurements. The highest activity was found with the sulphur compounds of cobalt and iron. The results are compared with those obtained with iron and cobalt melt chelates of the macrocyclic N₄ type (phthalocyanines, dibenzotetraazaannulenes) because knowledge is required about the reaction itself and the mechanism of the reduction of activity of the non-precious metal catalysts. The reaction scheme for the oxygen reduction is discussed and values of the rate constants of the electrochemical reactions are given.     

甲烷二氧化碳催化重整制合成气研究进展

催化剂研究是实现甲烷二氧化碳重整制合成气工业化的关键。对近年来甲烷二氧化碳重整制合成气的催化剂研究进行综述。介绍了贵金属催化剂、非贵金属催化剂及碳化物催化剂在甲烷二氧化碳重整反应中的应用及反应机理,并对催化剂体系研究方向进行展望。     

锂/空气电池非贵金属催化剂研究进展

锂/空气电池理论能量密度高、体积小、质量轻、价格低、无污染,是极具应用前景的二次电池。本文首先简要介绍了锂/空气电池的基本结构、原理和种类,随后重点讨论了近年来用于锂/空气电池的非贵金属催化剂的研究进展。这些催化剂主要包括过渡金属氧化物、过渡金属氮化物、碳材料以及过渡金属大环化合物等。最后认为,材料化学、纳米技术等学科的发展以及催化机理的阐明对发展高性能的锂/空气电池非贵金属催化剂起至关重要的作用。     

Chalcogenide metal centers for oxygen reduction reaction: Activity and tolerance

This mini-review summarizes materials design methods, oxygen reduction kinetics, tolerance to small organic molecules and fuel cell performance of chalcogenide metal catalysts, particularly, ruthenium (Ru_xSe_y) and non-precious transition metals (M_xX_y: M = Co, Fe and Ni; X = Se and S). These non-platinum catalysts are potential alternatives to Pt-based catalysts because of their comparable catalytic activity (Ru_xSe_y), low cost, high abundance and, in particular, a high tolerance to small organic molecules. Developing trends of synthesis methods, mechanism of oxygen reduction reaction and applications in direct alcohol fuel cells as well as the substrate effect are highlighted.     

Development of non-precious oxygen reduction reaction catalyst for polymer electrolyte membrane fuel cells based on substituted cobalt porphyrins

Active and stable cobalt-based non-precious metal catalysts for the oxygen reduction reaction (ORR) in PEM fuel cells were developed through high-temperature pyrolysis of metal-porphyrins supported on carbon. The roles of substituted porphyrins, carbon support, and catalyst loading on ORR activity were studied using rotating disc electrode (RDE) measurements. It was observed that the carbon support plays a major role in improving the catalytic activity. The results showed that among the supported catalysts, the homemade mesocarbon-supported cobalt-porphyrin catalyst with 20 wt% loading displayed higher ORR activity; the cell performance showed maximum current density of 1.1 A cm⁻² at 0.13 V in H₂/O₂ fuel cells.     

Highly methanol-tolerant non-precious metal cathode catalysts for direct methanol fuel cell

This work reports on the oxygen reduction activity of several non-precious metal (non-PGM) catalysts for oxygen reduction reaction (ORR) at the fuel cell cathode, including pyrolyzed CoTPP, FeTPP, H₂TMPP, and CoTMPP. Of the studied catalysts, pyrolyzed CoTMPP (Co-tetramethoxyphenylporphyrin) was found to perform significantly better than other materials. The catalyst underwent a thorough testing in both hydrogen-air polymer electrolyte fuel cell (PEFC) and direct methanol fuel cell (DMFC). It was found that CoTMPP cathode can sustain currents that are only 2-3 times lower than those obtained with a conventional Pt-black cathode in an H₂-air PEFC. DMFC experiments, including methanol crossover and methanol tolerance measurements, indicate high ORR selectivity of the CoTMPP catalyst. Based on results obtained to date, the CoTMPP-based catalyst offers promise for the use in conventional and mixed-reactant DMFCs operating with concentrated methanol feeds. However, hydrogen-air fuel cell life data, consisting of over 800 h of continuous cell operation, indicate that improvement to long-term stability of the CoTMPP catalyst will be required to make it practical.