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Binary anode electrocatalyst formulations were prepared by adsorption of phthalocyanine and tetraphenylporphyrin complexes of different transition metals on a commercial carbon supported platinum catalyst. Only after pyrolyzing the complexes at 700 °C under nitrogen were catalysts of some activity obtained. A binary Pt/Ni electrocatalyst prepared by this procedure exhibits considerable anodic catalytic activity in the acidic environment of the Nafion® electrolyte for reformate and direct methanol oxidation for more than 400 h without deterioration. Ternary electrocatalyst formulations Pt/Ru/W = 1/1/y were produced according to the Bönnemann method. The Pt/Ru/W catalyst of 1/1/1.5 (mol/mol/mol) composition is optimal. Compared to the Pt/Ru catalyst, it enhances the performance of reformate (H2 + 150 ppm CO) fuel cells by 50% and of direct methanol fuel cells (steam/methanol vapour = 50:1 mol/mol) by 80%. Attached to a GC electrode by a thin Nafion® film, the catalysts were also tested for methanol oxidation in aqueous methanol solutions in half cells by slow potential stepping. This procedure is useful for fast initial screening. 相似文献
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合适的电催化剂材料是质子交换膜燃料电池降低电极反应活化能、加快反应速度、提高电池能量转换效率的关键,尤其是用于阴极氧还原的电催化剂。Vuloan XC-72炭黑进行预处理后作为催化剂载体,采用分步化学沉积方法制备得到了炭黑负载的MnOx-Pt电催化剂。通过ICP、XRD、TEM、CV等物理和电化学手段测试和表征,结果表明;所得到电催化剂中锰氧化物的主要存在形式是隐钾锰矿型MnO2;三种催化剂样品中Mn的质量百分含量均为20%左右,而Pt的质量百分含量在5%左右。该催化剂具有较高的分散度,更高的氧还原起始电位和峰值电位,表现出良好的电催化氧还原性能,可作为质子交换膜燃料电池阴极氧还原的电催化剂;其电化学催化反应机理还有待于进一步深入的研究。 相似文献
14.
以石墨烯为载体,乙二醇为还原剂,采用油浴法,通过加入不同添加剂作为形状导向剂合成了Pt(100)晶面择优取向的催化剂,并探讨了催化剂的性能。利用X射线衍射仪(XRD)、透射电镜(TEM)、感应耦合等离子原子发射光谱 (ICP-AES)及扫描电镜(SEM)对所合成的催化剂进行微观表征,利用电化学工作站对所合成的催化剂进行电化学性能测试。结果表明,添加KBr参与合成的Pt(100)晶面取向的催化剂,其微观粒子的立方体形貌最为规整,且形成最彻底。同时,其电催化性能最优,电化学活性表面积为42.43m2/g,对乙醇氧化的峰值电流密度为417.67A/g,1100s的稳态电流密度值为149.50A/g,对乙醇催化氧化反应的活化能最低,对乙醇氧化峰电流密度保持率为82.26%。 相似文献
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Co nanoparticles (Co NPs) and nanoscale tungsten carbide (WC) are successfully synthesized simultaneously with mesoporous structured carbon black (C) using an innovative simple method, which is known as solution plasma processing (SPP), and NPs are also loaded onto carbon black at the same time by SPP. The introduction of Co NPs led to not only superior oxygen reduction reaction (ORR) activity in terms of onset potential and peak potential, but also to a more efficient electron transfer process compared to that of pure WC. Co-WC/C also showed durability for long-term operation better than that of commercial Pt/C. These results clearly demonstrate that the presence of Co NPs significantly enhanced the ORR and charge transfer number of neighboring WC NPs in ORR activities. In addition, it was proved that SPP is a simple method (from synthesis of NPs and carbon black to loading on carbon black) for the large-scale synthesis of NP-carbon composite. Therefore, SPP holds great potential as a candidate for next-generation synthetic methods for the production of NP-carbon composites. 相似文献
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Huanran Zheng Shibin Wang Shoujie Liu Jiao Wu Jianping Guan Qian Li Yuchao Wang Yu Tao Shouyao Hu Yu Bai Jinxian Wang Xiang Xiong Yu Xiong Yongpeng Lei 《Advanced functional materials》2023,33(40):2300815
The rational design and construction of efficient and inexpensive bifunctional oxygen electrocatalysts are highly desirable for the development of rechargeable Zn–air batteries (ZABs). Although single-atom Fe sites anchored on N-doped carbon catalysts (Fe1/NC) ensure high oxygen reduction reaction activity, their unitary atomically dispersed active center faces difficult condition in catalyzing oxygen evolution reaction simultaneously. Herein, a composite catalyst containing heterointerface between Fe1/NC and selenides ((Fe,Co)Se2) is constructed. The obtained (Fe,Co)Se2@Fe1/NC exhibits extremely narrow potential gap of 0.616 V and remarkable stability in alkaline media, outperforming the benchmark catalysts (Pt/C+RuO2: 0.720 V). Experimental results and density functional theory calculations reveal that heterointerface between Fe1/NC and (Fe,Co)Se2 accelerates the electron transfer and provides more moderate adsorption sites, which endow (Fe,Co)Se2@Fe1/NC with extremely high bifunctional oxygen catalytic activity. This study not only provides a superior bifunctional catalyst for ZABs, but also enriches the application of single-atom catalysts in multifunctional energy storage and conversion devices. 相似文献
19.
Kun Guo Zhimin He Song Lu Pengjun Zhang Ning Li Lipiao Bao Zhixin Yu Li Song Xing Lu 《Advanced functional materials》2023,33(29):2302100
Carbon nano-onions (CNOs) as a novel form of carbon materials hold peculiar structural features but their electrocatalytic applications are largely discouraged by the demanding synthesis conditions (e.g., ≥1500 °C and vacuum). Using C60 fullerene molecules as the sacrificial seeds and melamine as the main feedstock, herein, a novel strategy for the facile construction of CNOs nanoparticles is presented with ultrafine sizes (≈5 nm) at relatively low temperatures (≤900 °C) and atmospheric pressure. During the calcination, in-depth characterizations reveal that C60 can retain the melamine-derived graphitic carbon nitride from complete sublimation at high temperatures (≥700 °C). Owing to the N removal and subsequent pentagon generation, severely deformed graphitic fragments together with the disintegrated C60 molecules merge into larger sized nanosheets with high curvature, eventually leading to the formation of N-doped defect-rich CNOs. Owing to the integration of multiple favorable structural features of pentagons, edges, and N dopants, the CNOs obtained at 900 °C present superior oxygen reduction half-wave potential (0.853 VRHE) and zinc–air cathode performance to the commercial Pt/C (0.838 VRHE). Density functional theory calculation further uncovers that the carbon atoms adjacent to the N-doped edged pentagons are turned into the ORR-active sites with O2 protonation as the rate-determining step. 相似文献
20.
微型直接甲醇燃料电池的研究进展 总被引:1,自引:0,他引:1
直接甲醇燃料电池以其高效、低温、结构简单、易于微型化等优点成为世界燃料电池研究的一个热点。讨论了微型直接甲醇燃料电池的一些关键技术,如电催化剂、质子交换膜以及膜电极组件。介绍了国内外微型直接甲醇燃料电池的研究进展;展望了这类电池的发展前景。 相似文献