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71.
Well-homogenized PtRu/C electrocatalysts possessing high specific activity for methanol electro-oxidation were prepared by a co-impregnation method from carbon black and ethanolic solutions of Pt(NH3)2(NO2)2 and RuNO(NO3)
x
. The specific activity for methanol electro-oxidation increased with an increase in the PtRu particle size. A similar size effect was observed for Pt/C electrocatalysts. The size effect was discussed by considering a model catalyst method. 相似文献
72.
73.
Dr. Yuebin Lian Dr. Wenjuan Yang Chufeng Zhang Hao Sun Prof. Zhao Deng Dr. Wenjie Xu Prof. Li Song Prof. Zhongwen Ouyang Prof. Zhenxing Wang Prof. Jun Guo Prof. Yang Peng 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(1):292-300
Reversible oxygen conversion is important for various green energy technologies. Herein we synthesize a series of bimetallic coordination polymers by varying the Ni/Co ratio and using HITP (HITP=2,3,6,7,10,11-hexaiminotriphenylene) as the ligand, to interrogate the role of metal centres in modulating the activity of the oxygen reduction reaction (ORR). Co3HITP2 and Ni3HITP2 are compared. Unpaired 3d electrons in Co3HITP2 result in less coplanarity but more radical character. Thus, despite of a reduced crystallinity and conductivity, the best ORR activity, comparable to 20 % Pt/C, is obtained for Co3HITP2, showing the 3d orbital configuration of the metal centre promotes ORR. Experimental and DFT studies show a transition of ORR pathway from four-electron for Co3HITP2 to two-electron for Ni3HITP2. Rechargeable zinc–air batteries using Co3HITP2 as the air cathode catalyst demonstrate excellent energy efficiency and stability. 相似文献
74.
Yuchen Xiao Anh N. Hong Dandan Hu Yanxiang Wang Prof. Xianhui Bu Prof. Pingyun Feng 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(71):16358-16365
Zeolitic imidazolate frameworks (ZIFs) are traditionally synthesized solvothermally by using cost- and waste-incurring organic solvents. Here, a direct synthesis method is reported for ZIF-8, ZIF-67, and their heterometallic versions from solid precursors only. This solvent-free crystallization method not only completely avoids organic solvents, but also provides an effective path for the synthesis of homogeneous mixed-metal ZIFs. Furthermore, under templating by NaCl/ZnCl2 eutectic salt, carbonization of the ZIF materials gives rise to a series of N-containing high-surface-area carbon materials with impressive catalytic properties for the oxygen reduction reaction. 相似文献
75.
Ding Chen Jiawei Zhu Dr. Zonghua Pu Prof. Shichun Mu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(48):12257-12271
Pt-group metal (PGM) electrocatalysts with unique electronic structures and irreplaceable comprehensive properties play crucial roles in electrocatalysis. Anion engineering can create a series of PGM compounds (such as RuP2, IrP2, PtP2, RuB2, Ru2B3, RuS2, etc.) that provide a promising prospect for improving the electrocatalytic performance and use of Pt-group noble metals. This review seeks the electrochemical activity origin of anion-modulated PGM compounds, and systematically analyzes and summarizes their synthetic strategies and energy-relevant applications in electrocatalysis. Orientation towards the sustainable development of nonfossil resources has stimulated a blossoming interest in the design of advanced electrocatalysts for clean energy conversion. The anion-modulated strategy for Pt-group metals (PGMs) by means of anion engineering possesses high flexibility to regulate the electronic structure, providing a promising prospect for constructing electrocatalysts with superior activity and stability to satisfy a future green electrochemical energy conversion system. Based on the previous work of our group and others, this review summarizes the up-to-date progress on anion-modulated PGM compounds (such as RuP2, IrP2, PtP2, RuB2, Ru2B3, RuS2, etc.) in energy-related electrocatalysis from the origin of their activity and synthetic strategies to electrochemical applications including hydrogen evolution reaction (HER), oxygen evolution reaction (OER), oxygen reduction reaction (ORR), hydrogen oxidation reaction (HOR), N2 reduction reaction (NRR), and CO2 reduction reaction (CO2RR). At the end, the key problems, countermeasures and future development orientations of anion-modulated PGM compounds toward electrocatalytic applications are proposed. 相似文献
76.
近年来, 原子催化剂(ACs)引起了广泛的研究关注. 目前该领域的长足发展受限于贵金属的使用和单原子催化剂(SACs)的性能有限. 本文总结了利用密度泛函理论(DFT)和机器学习(ML)方法筛选高效的基于石墨炔(GDY)的原子催化剂的工作. 研究表明, Pd, Co, Pt和Hg可以形成稳定的零价过渡金属-石墨炔组合(TM-GDY), 而镧系-过渡金属的双原子催化剂(Ln-TM DAC)组合通过f-d轨道耦合作用可以获得有效的催化性能提升. 进一步分析表明, 主族元素与过渡金属和镧系金属的结合可以通过p轨道耦合保持高电活性, 从而构成高度稳定的GDY-DAC系统, 机器学习算法也揭示了s,p轨道的作用. 此外, 理论算法技术在筛选催化水分解析氢反应(HER)的高效组合上也表现出了优越性, 创新性地预测了石墨炔-原子催化剂在实际催化反应中的潜能. 本综合评述可为未来设计新型原子催化剂提供新的思路与策略. 相似文献
77.
78.
Pt-based alloys are the optimal electrocatalysts for oxygen reduction reaction(ORR) currently. Dealloying of Pt-based alloys has shown to be an effective approach to improving ORR activity. Electrochemical dealloying is controllable for morphology by changing electrochemical parameters but is difficult to scale up due to complex operation and energy consumption. Chemical dealloying is suitable for a large scale but it is not easy to control the morphology because highly corrosive acids(HNO3 or H2SO4) are commonly used. In this work, a facile chemical dealloying method for Pt3Co/C has been employed to synthesize elec-trocatalysts for ORR using weak acids and buffer solutions of different pH, which could slow down the dissolution rate for Co atoms and increase the diffusion time for Pt atoms to improve ORR activity. It can be observed that the mass activities(MA) of the Pt3Co/C alloy after dealloying with H3PO4 and NaH2PO4/Na2HPO4 buffer solution of pH=6 are close to that after electrochemical dealloying process, and are more than two times that of commercial Pt/C. In addition, Pt3Co/C after dealloying with a buffer solution of pH=6 only showed a slight degradation in the half-wave potential and electrochemical surface area(ECSA) after stability test for 5000 cycles, which is more stable than commercial Pt/C. It shows that by controlling pH of the solvent, the ORR activity can be further increased. This facile approach provides a new strategy to control morphology of Pt-based electrocatalysts by chemical dealloying, which can contribute to promising application for cathodic electrocatalysts design of proton exchange membrane fuel cells (PEMFCs). 相似文献
79.
《Electroanalysis》2003,15(18):1460-1464
The electroactive composite containing tris(2,2′‐bipyridine) ruthenium(II) and 12‐molybdophosphate (RuPMo12) was synthesized and first used as a bifunctional electrocatalyst to fabricate a chemically bulk‐modified carbon paste electrode (RuPMo12‐CPE) by direct mixing. The electrochemical behavior of the RuPMo12‐CPE was studied by cyclic voltammetry. The RuPMo12‐CPE presents good electrocatalytic activity not only toward the reduction of hydrogen peroxide and bromate, which is attributed to the function of molybdophosphate, but also toward the oxidation of arsenite, which is primarily attributed to the function of tris(2,2′‐bipyridine) ruthenium(II). The remarkable advantage of the RuPMo12‐CPE is its good stability owing to the insolubility of RuPMo12 and reproducibility of surface renewal. 相似文献
80.
S. A. Grigor’ev E. K. Lyutikova E. G. Pritulenko D. P. Samsonov V. N. Fateev 《Russian Journal of Electrochemistry》2006,42(11):1251-1254
Palladium-based nanostructured electrocatalysts on the Vulcan XC-72 carbon support for fuel cells with solid polymer electrolyte are synthesized and studied. In particular, electrochemical studies of the synthesized catalysts are carried out and membrane-electrode assemblies are assembled on their basis and tested. The test results indicate that platinum can be replaced with palladium in the hydrogen electrode of the fuel cells. 相似文献