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Platinum on nitrogen doped graphene and tungsten carbide supports for ammonia electro-oxidation reaction

《化学科学与工程前沿(英文)》 2022年 第16卷 第6期   页码 930-938 doi: 10.1007/s11705-021-2130-2

摘要: Ammonia electrooxidation reaction involving multistep electron-proton transfer is a significant reaction for fuel cells, hydrogen production and understanding nitrogen cycle. Platinum has been established as the best electrocatalyst for ammonia oxidation in aqueous alkaline media. In this study, Pt/nitrogen-doped graphene (NDG) and Pt/tungsten monocarbide (WC)/NDG are synthesized by a wet chemistry method and their ammonia oxidation activities are compared to commercial Pt/C. Pt/NDG exhibits a specific activity of 0.472 mA∙cm–2, which is 44% higher than commercial Pt/C, thus establishing NDG as a more effective support than carbon black. Moreover, it is demonstrated that WC as a support also impacts the activity with further 30% increase in comparison to NDG. Surface modification with Ir resulted in the best electrocatalytic activity with Pt-Ir/WC/NDG having almost thrice the current density of commercial Pt/C. This work adds insights regarding the role of NDG and WC as efficient supports along with significant impact of Ir surface modification.

关键词: Ammonia electro-oxidation reaction     electrocatalyst supports     platinum     nitrogen doped graphene     tungsten carbide    

Study on the growth of platinum nanowires as cathode catalysts in proton exchange membrane fuel cells

Ruiqing Wang, Xiaolan Cao, Sheng Sui, Bing Li, Qingfeng Li

《化学科学与工程前沿(英文)》 2022年 第16卷 第3期   页码 364-375 doi: 10.1007/s11705-021-2052-z

摘要: The platinum nanowires have been verified to be a promising catalyst to promote the performance of proton exchange membrane fuel cells. In this paper, accurately controlled growth of nanowires in a carbon matrix is achieved for reducing Pt loading. The effects of formic acid concentration and reaction temperature on the morphology and size of the Pt nanowires, as well as their electrochemical performances in a single cell, are investigated. The results showed that the increase in the formic acid concentration results in a volcano trend with the length of Pt nanowires. With increasing reduction temperature, the diameter of Pt nanowires increases while Pt particles evolve from one-dimensional to zero-dimensional up to 40 °C. A mechanism of the Pt nanowires growth is proposed. The optimized Pt nanowires electrode exhibits a power density (based on electrochemical active surface area) 79% higher than conventional Pt/C one. The control strategy obtained contributes to the design and control of novel nanostructures in nano-synthesis and catalyst applications.

关键词: Pt nanowires     morphology     structure control     in situ growth mechanism     proton exchange membrane fuel cells    

Hydro-pyrolysis of lignocellulosic biomass over alumina supported Platinum, Mo

Songbo He, Jeffrey Boom, Rolf van der Gaast, K. Seshan

《化学科学与工程前沿(英文)》 2018年 第12卷 第1期   页码 155-161 doi: 10.1007/s11705-017-1655-x

摘要: In-line hydro-treatment of bio-oil vapor from fast pyrolysis of lignocellulosic biomass (hydro-pyrolysis of biomass) is studied as a method of upgrading the liquefied bio-oil for a possible precursor to green fuels. The nobel metal (Pt) and non-noble metal catalysts (Mo C and WC) were compared at 500 °C and atmospheric pressure which are same as the reaction conditions for fast pyrolysis of biomass. Results indicated that under the pyrolysis conditions, the major components, such as acids and carbonyls, of the fast pyrolysis bio-oil can be completely and partially hydrogenated to form hydrocarbons, an ideal fossil fuel blend, in the hydro-treated bio-oil. The carbide catalysts perform equally well as the Pt catalyst regarding to the aliphatic and aromatic hydrocarbon formation (ca. 60%), showing the feasibility of using the cheap non-noble catalysts for hydro-pyrolysis of biomass.

关键词: bio-oil     pyrolysis     hydro-deoxygenation (HDO)     non-noble metal catalysts     hydro-treatment    

Oxygen reduction electrocatalysis: From conventional to single-atomic platinum-based catalysts for proton

《能源前沿(英文)》 doi: 10.1007/s11708-023-0907-3

摘要: Platinum (Pt)-based materials are still the most efficient and practical catalysts to drive the sluggish kinetics of cathodic oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs). However, their catalysis and stability performance still need to be further improved in terms of corrosion of both carbon support and Pt catalyst particles as well as Pt loading reduction. Based on the developed synthetic strategies of alloying/nanostructuring Pt particles and modifying/innovating supports in developing conventional Pt-based catalysts, Pt single-atom catalysts (Pt SACs) as the recently burgeoning hot materials with a potential to achieve the maximum utilization of Pt are comprehensively reviewed in this paper. The design thoughts and synthesis of various isolated, alloyed, and nanoparticle-contained Pt SACs are summarized. The single-atomic Pt coordinating with non-metals and alloying with metals as well as the metal-support interactions of Pt single-atoms with carbon/non-carbon supports are emphasized in terms of the ORR activity and stability of the catalysts. To advance further research and development of Pt SACs for viable implementation in PEMFCs, various technical challenges and several potential research directions are outlined.

关键词: oxygen reduction electrocatalysis     Pt single-atom catalysts     conventional Pt-based catalysts     design thoughts and synthesis     metal-support interactions    

Synthesis and electrocatalytic property of cubic and spherical nanoparticles of cobalt platinum alloys

Xiaowei TENG, Hong YANG,

《化学科学与工程前沿(英文)》 2010年 第4卷 第1期   页码 45-51 doi: 10.1007/s11705-009-0308-0

摘要: This paper describes the morphological control and electrocatalytic property of CoPt nanoparticles. Both cubic and spherical CoPt nanoparticles were made using cobalt carbonyl and platinum 2,4-pentanedionate under different reaction temperatures in the presence of capping reagents, which included adamantanecarboxylic acid and hexadecylamine. Effects of heterogeneous species on shape of the CoPt nanoparticles were examined by replacing cobalt carbonyl with silver acetylacetonate. Our results suggest that the formation of different shapes of CoPt particles could be attributed to the affinity between cobalt and platinum, and the effects of capping agents. The size and shape dependent electrocatalytic properties of these nanoparticles were examined based on the direct methanol oxidation reaction.

关键词: spherical     2     4-pentanedionate     adamantanecarboxylic     acetylacetonate     electrocatalytic    

Bevacizumab in combination with pemetrexed and platinum for elderly patients with advanced non-squamous

《医学前沿(英文)》 2022年 第16卷 第4期   页码 610-617 doi: 10.1007/s11684-021-0827-8

摘要: Bevacizumab, an anti-VEGF monoclonal antibody, has significantly improved the clinical outcomes of patients with advanced non-squamous NSCLC (ns-NSCLC). However, the safety and efficacy of bevacizumab for elderly patients with advanced NSCLC require further investigation. Thus, 59 patients were included in the present retrospective study, 22 patients in the bevacizumab plus pemetrexed and platinum (B+PP) group, and 37 patients in the pemetrexed and platinum (PP) group. For the entire cohort of patients, the median OS was 33.3 months, and the 1-year and 2-year overall survival rates were 88.5% and 67.8%, respectively. The median OS and 1-year and 2-year OS rates were 20.5 months, 70.3% and 0%, respectively, in the B+PP group and 33.4 months, 97.0% and 89.4%, respectively, in the PP group (P <0.001). The incidence of grade≥3 adverse events was higher in the B+PP group than in the PP group (27.3% vs. 10.8%, respectively; P=0.204). Univariate and multivariate analyses suggested that the receipt of≥5 cycles of first-line chemotherapy was an independent favorable prognostic factor for OS, whereas the addition of bevacizumab was an unfavorable prognostic factor. With increased toxicities, the addition of bevacizumab to PP does not improve the overall survival of elderly patients with advanced ns-NSCLC.

关键词: bevacizumab     elderly patient     advanced non-small-cell lung cancer     overall survival     toxicity    

走向白金社会:工程科学面临的挑战

Hiroshi Komiyama

《工程(英文)》 2015年 第1卷 第1期   页码 18-20 doi: 10.15302/J-ENG-2015019

Recent advances in cathode electrocatalysts for PEM fuel cells

Junliang ZHANG

《能源前沿(英文)》 2011年 第5卷 第2期   页码 137-148 doi: 10.1007/s11708-011-0153-y

摘要: Great progress has been made in the past two decades in the development of the electrocatalysts for proton exchange membrane fuel cells (PEMFCs). This review article is focused on recent advances made in the kinetic-activity improvement on platinum- (Pt-) based cathode electrocatalysts for the oxygen reduction reaction (ORR). The origin of the limited ORR activity of Pt catalysts is discussed, followed by a review on the development of Pt alloy catalysts, Pt monolayer catalysts, and shape- and facet-controlled Pt-alloy nanocrystal catalysts. Mechanistic understanding is reviewed as well on the factors contributing to the enhanced ORR activity of these catalysts. Finally, future directions for PEMFC catalyst research are proposed.

关键词: proton exchange membrane fuel cells (PEMFCs)     cathode electrocatalysts     platinum     oxygen reduction reaction (ORR)    

Concentrations of anthropogenic Pt and Pd in urban roadside soils in Xuzhou, China

WANG Xuesong, SUN Cheng

《环境科学与工程前沿(英文)》 2008年 第2卷 第4期   页码 475-479 doi: 10.1007/s11783-008-0071-3

摘要: The potential accumulation of platinum group elements (PGE) in the environment from automobile catalysts is high in urban areas, with the major sinks being roadside soils. Therefore, this investigation presented the detailed study on characterized concentrations of Pt and Pd and their enrichment ratios in urban roadside soils in Xuzhou, China in March 2003. Data from 21 roadside topsoil samples analyzed by inductively coupled plasma-mass spectrometer (ICP-MS) illustrated that the medians of concentrations of Pt and Pd were 2.9 and 2.8 ng/g, respectively. Hierarchical clustering analysis indicated that Pt and Pd were mainly from traffic emissions. Compared to unpolluted soils, computation of Pt and Pd enrichment ratios suggested that the Xuzhou roadside soils had average enrichment factors of 3.53 for Pt (in range of 1.22–5.73) and of 3.37 for Pd (in range of 1.35–4.46). Lower Pt/Pd ratios (in range of 0.35–2.86) in relation to similar studies in other countries were observed, which might be due to the different Pt/Pd ratios in Chinese automobile catalytic converters. Moreover, fine fraction (<250 ?m) contained higher concentrations of Pt and Pd compared to the coarse fraction (250–500 ?m).

关键词: platinum     detailed     different     Hierarchical     automobile catalytic    

Preparation and influence of performance of anodic catalysts for direct methanol fuel cell

WANG Zhenbo, YIN Geping, SHI Pengfei

《化学科学与工程前沿(英文)》 2007年 第1卷 第1期   页码 20-25 doi: 10.1007/s11705-007-0005-9

摘要: This research aims at increasing the utilization of platinum-ruthenium alloy (Pt-Ru) catalysts and thus lowering the catalyst loading in anodes for methanol electrooxidation. The direct methanol fuel cell s (DMFC) anodic catalysts, Pt-Ru/C, were prepared by chemical reduction with a reducing agent added in two kinds of solutions under different circumstances. The reducing agent was added in hot solution with the protection of inert gases or just air, and in cold solution with inert gases. The catalysts were treated at different temperatures. Their performance was tested by cyclic voltammetry and potentiostatic polarization by utilizing their inherent powder microelectrode in 0.5 mol/L CHOH and 0.5 mol/L HSO solution. The structures and micro-surface images of the catalysts were determined and observed by X-ray diffraction and transmission electron microscopy, respectively. The catalyst prepared in inert gases showed a better catalytic performance for methanol electrooxidation than that prepared in air. It resulted in a more homogeneous distribution of the Pt-Ru alloy in carbon. Its size is small, only about 4.5 nm. The catalytic performance is affected by the order of the reducing agent added. The performance of the catalyst prepared by adding the reductant at constant temperature of the solution is better than that prepared by adding it in the solution at 0?C and then heating it up to the reducing temperature. The structure of the catalyst was modified, and there was an increase in the conversion of ruthenium into the alloyed state and an increase in particle size with the ascension of heat treatment temperature. In addition, the stability of the catalyst was improved after heat treatment.

关键词: catalyst prepared     stability     ascension     potentiostatic polarization     platinum-ruthenium    

Fabrication of ionic polymer-metal composites (IPMCs) and robot design

Hanmin PENG, Qingjun Ding, Huafeng LI

《机械工程前沿(英文)》 2009年 第4卷 第3期   页码 332-338 doi: 10.1007/s11465-009-0046-5

摘要: This paper describes a method for preliminary manufacturing experiments on a type of smart materials—ionic polymer-metal composites (IPMCs). They belong to EAP materials and are famous for their capability of huge displacement within a low voltage (1–3 V). With best operation quality in the humid environment, they can be made as underwater robots in simple structures. In this paper, two purposes are embodied. One focuses on the research on the IPMCs characteristics, including the actuating principle, manufacturing process, and parameters of performance. The other is that a relevant robot driven by IPMCs strips is designed. According to imitation propulsion mechanism of undulatory fins, IPMCs are designed for a novel bionic water vehicle propelled by undulatory multiple fish-like fins (made by IPMCs). The robot consists of three fins on the bottom tightly contacting by plastic foils with each other.

关键词: ionic polymer-metal composites (IPMCs)     artificial muscles     actuator     bionic robot     platinum-plated    

A review of Pt-based electrocatalysts for oxygen reduction reaction

Changlin ZHANG, Xiaochen SHEN, Yanbo PAN, Zhenmeng PENG

《能源前沿(英文)》 2017年 第11卷 第3期   页码 268-285 doi: 10.1007/s11708-017-0466-6

摘要: Development of active and durable electrocatalyst for oxygen reduction reaction (ORR) remains one challenge for the polymer electrolyte membrane fuel cell (PEMFC) technology. Pt-based nanomaterials show the greatest promise as electrocatalyst for this reaction among all current catalytic structures. This review focuses on Pt-based ORR catalyst material development and covers the past achievements, current research status and perspectives in this research field. In particular, several important categories of Pt-based catalytic structures and the research advances are summarized. Key factors affecting the catalyst activity and durability are discussed. An outlook of future research direction of ORR catalyst research is provided.

关键词: oxygen reduction reaction (ORR)     electrocatalysis     platinum catalyst     activity     durability    

Catalytic oxidation of CO over Pt/Fe

Zihao Li, Yang Geng, Lei Ma, Xiaoyin Chen, Junhua Li, Huazhen Chang, Johannes W. Schwank

《环境科学与工程前沿(英文)》 2020年 第14卷 第4期 doi: 10.1007/s11783-020-1244-y

摘要: Abstract • Strong metal-support interaction exists on Pt/Fe3O4 catalysts. • Pt metal particles facilitate the formation of oxygen vacancies on Fe3O4. • Fe3O4 supports enhance the strength of CO adsorption on Pt metal particles. The self-inhibition behavior due to CO poisoning on Pt metal particles strongly impairs the performance of CO oxidation. It is an effective method to use reducible metal oxides for supporting Pt metal particles to avoid self-inhibition and to improve catalytic performance. In this work, we used in situ reductions of chloroplatinic acid on commercial Fe3O4 powder to prepare heterogeneous-structured Pt/Fe3O4 catalysts in the solution of ethylene glycol. The heterogeneous Pt/Fe3O4 catalysts achieved a better catalytic performance of CO oxidation compared with the Fe3O4 powder. The temperatures of 50% and 90% CO conversion were achieved above 260°C and 290°C at Pt/Fe3O4, respectively. However, they are accomplished on Fe3O4 at temperatures higher than 310°C. XRD, XPS, and H2-TPR results confirmed that the metallic Pt atoms have a strong synergistic interaction with the Fe3O4 supports. TGA results and transient DRIFTS results proved that the Pt metal particles facilitate the release of lattice oxygen and the formation of oxygen vacancies on Fe3O4. The combined results of O2-TPD and DRIFTS indicated that the activation step of oxygen molecules at surface oxygen vacancies could potentially be the rate-determining step of the catalytic CO oxidation at Pt/Fe3O4 catalysts. The reaction pathway involves a Pt-assisted Mars-van Krevelen (MvK) mechanism.

关键词: Strong metal-support interaction (SMSI)     Surface oxygen vacancy     Lattice oxygen     Magnetite     Platinum metals    

标题 作者 时间 类型 操作

Platinum on nitrogen doped graphene and tungsten carbide supports for ammonia electro-oxidation reaction

期刊论文

Study on the growth of platinum nanowires as cathode catalysts in proton exchange membrane fuel cells

Ruiqing Wang, Xiaolan Cao, Sheng Sui, Bing Li, Qingfeng Li

期刊论文

Hydro-pyrolysis of lignocellulosic biomass over alumina supported Platinum, Mo

Songbo He, Jeffrey Boom, Rolf van der Gaast, K. Seshan

期刊论文

Oxygen reduction electrocatalysis: From conventional to single-atomic platinum-based catalysts for proton

期刊论文

Synthesis and electrocatalytic property of cubic and spherical nanoparticles of cobalt platinum alloys

Xiaowei TENG, Hong YANG,

期刊论文

Bevacizumab in combination with pemetrexed and platinum for elderly patients with advanced non-squamous

期刊论文

走向白金社会:工程科学面临的挑战

Hiroshi Komiyama

期刊论文

Recent advances in cathode electrocatalysts for PEM fuel cells

Junliang ZHANG

期刊论文

Concentrations of anthropogenic Pt and Pd in urban roadside soils in Xuzhou, China

WANG Xuesong, SUN Cheng

期刊论文

Preparation and influence of performance of anodic catalysts for direct methanol fuel cell

WANG Zhenbo, YIN Geping, SHI Pengfei

期刊论文

Fabrication of ionic polymer-metal composites (IPMCs) and robot design

Hanmin PENG, Qingjun Ding, Huafeng LI

期刊论文

A review of Pt-based electrocatalysts for oxygen reduction reaction

Changlin ZHANG, Xiaochen SHEN, Yanbo PAN, Zhenmeng PENG

期刊论文

Catalytic oxidation of CO over Pt/Fe

Zihao Li, Yang Geng, Lei Ma, Xiaoyin Chen, Junhua Li, Huazhen Chang, Johannes W. Schwank

期刊论文