Nitrogen-doped coatings on carbon nanotubes and their stabilizing effect on Pt nanoparticles

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.A homogeneous coating of nitrogen-doped carbon on carbon nanotubes is performed using ionic liquids. The N-doped material is employed as a support for nanoparticles. Electrochemical degradation behavior is monitored in situ and compared to an unmodified material. The strongly enhanced stability is explained on the basis of a Pt–nitrogen interaction.DFG, EXC 314, Unifying Concepts in Catalysi

FORMATION OF A VALUE PROPOSITION FOR CLIENTS: THEORETICAL APPROACHES AND UNDERSTANDING OF REPRESENTATIVES OF RUSSIAN COMPANIES

The paper is devoted to a comparative analysis of theoretical approaches to the formation of a value proposition and its understanding by representatives of Russian companies. The existing theoretical approaches to the formation of a value proposition are considered, as well as the main tools used in its formation in practice. To determine the theoretical approaches, more than 50 articles from leading economic journals were analyzed. To analyze the understanding of the value proposition, Russian companies conducted in–depth semi-structured interviews with managers of 84 Russian and foreign companies representing customer service departments, sales departments, innovation activities, strategic management, marketing and brand management departments.The analysis has shown that for most employees of companies, the concepts of a value approach in management and a value proposition are limited to standard categories, such as price, quality, and direct satisfaction of needs. This is especially true for representatives of Russian companies and firms that conduct their business only within Russia and CIS countries. While representatives of international companies noted the importance of the entire range of value formation tools in one way or another evenly, respondents from Russian companies clearly relied on product components and price in their answers. It should also be noted the leadership of product tools in both cases, and if Russian respondents focused only on the quality of the product in their answers, then representatives of international companies often noted the importance of the assortment and uniqueness of products.The result of the study was to determine the importance and place in the process of forming a value proposition of such tools as joint value creation with the consumer and the involvement of personnel in joint value creation.The author's approach to the formation of value proposition by companies is proposed in the article. The proposed matrix model allows you to quickly determine which factors and tools companies need to focus on first

ФОРМИРОВАНИЕ ЦЕННОСТНОГО ПРЕДЛОЖЕНИЯ ДЛЯ КЛИЕНТОВ: ТЕОРЕТИЧЕСКИЕ ПОДХОДЫ И ПОНИМАНИЕ ПРЕДСТАВИТЕЛЕЙ РОССИЙСКИХ КОМПАНИЙ

The paper is devoted to a comparative analysis of theoretical approaches to the formation of a value proposition and its understanding by representatives of Russian companies. The existing theoretical approaches to the formation of a value proposition are considered, as well as the main tools used in its formation in practice. To determine the theoretical approaches, more than 50 articles from leading economic journals were analyzed. To analyze the understanding of the value proposition, Russian companies conducted in–depth semi-structured interviews with managers of 84 Russian and foreign companies representing customer service departments, sales departments, innovation activities, strategic management, marketing and brand management departments.The analysis has shown that for most employees of companies, the concepts of a value approach in management and a value proposition are limited to standard categories, such as price, quality, and direct satisfaction of needs. This is especially true for representatives of Russian companies and firms that conduct their business only within Russia and CIS countries. While representatives of international companies noted the importance of the entire range of value formation tools in one way or another evenly, respondents from Russian companies clearly relied on product components and price in their answers. It should also be noted the leadership of product tools in both cases, and if Russian respondents focused only on the quality of the product in their answers, then representatives of international companies often noted the importance of the assortment and uniqueness of products.The result of the study was to determine the importance and place in the process of forming a value proposition of such tools as joint value creation with the consumer and the involvement of personnel in joint value creation.The author's approach to the formation of value proposition by companies is proposed in the article. The proposed matrix model allows you to quickly determine which factors and tools companies need to focus on first.Статья посвящена сравнительному анализу теоретических подходов к формированию ценностного предложения и его пониманию представителями российских компаний. Рассматриваются существующие теоретические подходы к формированию ценностного предложения, а также основные инструменты, используемые при его формировании на практике. Для определения теоретических подходов было проанализировано более 50 статей из ведущих экономических журналов. Для анализа понимания ценностного предложения российскими компаниями были проведены глубинные полуструктурированные интервью с менеджерами 84 российских и зарубежных компаний, представляющими отделы по работе с клиентами, отделы продаж, инновационную деятельность, отделы стратегического управления, маркетинга и бренд-менеджмента.Проведенный анализ показал, что у большинства сотрудников компаний понятия ценностного подхода в управлении и ценностного предложения ограничиваются стандартными категориями, такими как цена, качество, прямое удовлетворение потребности. В особенности это характерно для представителей российских компаний и фирм, ведущих свой бизнес только внутри России и стран СНГ. Если представители международных компаний отмечали важность всего спектра инструментов формирования ценности в той или иной мере равномерно, то респонденты из российских компаний в своих ответах явно опирались на продуктовые составляющие и цену. Также следует отметить лидерство продуктовых инструментов в обоих случаях, причем если российские респонденты основной упор в своих ответах делали только на качество продукта, то представители международных компаний часто отмечали важность ассортимента и уникальности продукции. Результатом исследования стало определение важности и места в процессе формирования ценностного предложения таких инструментов, как совместное создание ценности с потребителем и вовлечение в совместное создание ценности персонала.В статье предложен авторский подход к формированию ценностного предложения компаниями. Предложенная матричная модель позволяет достаточно быстро определить, на каких факторах и инструментах компаниям необходимо  сфокусироваться в первую очередь

THEORY AND SYNTHESIS OF GRAIN CLEANERS WITH FLEXIBLE WORKING HEADS

There the study objects are the grain cleaners with the flexible working heads, their processes, the structures and the characteristics of working heads, the ear mass and the multicomponent grain blends. The purpose is to develop the theoretical foundations for the analysis and for the optimum synthesis of new manners and devices, which are new in the main, which raise appreciably the rate of separation process of grain blends and of impactless thrashing process of ear mass with the use of grain cleaner. The separation theory of grain by the high-rate grain cleaners, the mechanical-and-production foundations for the rate raising of thrashing and separation of grain in the thrashing-cleaning device, the construction methods of design mathematical simulators and of optimum synthesis of grain cleaners have been developed. The algorithms and the software package of simulation and optimum synthesis of grain cleaners, the manners and the devices, which were realized as the high-effective grain cleaner units, which taken place in the departmental and farming tests, have been developed. The specific output of grain cleaners was risen 4 - 4,5 times at the decrease of material consumption 2 - 2,4 times. The specific capacity of thrashing was decreased 6 times, the breaking of seeds is excluded. The study results have been introduced in BTG-20, BTG-50/25 and ATG-35 grain cleaner units, are used in the Krasnoyarsk Works of Combine Harvesters, in the educational process of colleges of agriculture in the Russian FederationAvailable from VNTIC / VNTIC - Scientific & Technical Information Centre of RussiaSIGLERURussian Federatio

The impact of the morphology of the carbon support on the activity and stability of nanoparticle fuel cell catalysts

This study explores how the morphology of nanostructured carbons impacts the morphological stability of supported Pt fuel cell nanoparticle catalysts under extended potential cycling. Using in situ small angle X ray scattering SAXS , we monitor the evolution of key structural parameters of four different Pt carbon catalyst couples, involving carbons with vastly different porosity characteristics hollow carbons, nanotubes, and carbon blacks . In line with the size of supported Pt nanoparticles, the intrinsic specific electrochemical oxygen reduction reaction ORR activities of all samples were comparable. However, counter to common sense, a non monotonic trend between the carbon surface area and the ORR mass based activity, coupled with a similar relative loss in the electrochemical surface area ECSA , was observed. This is explained in terms of a varying effective ECSA, which is sensitively dependent on the morphology of the support. In situ SAXS monitoring revealed a mainly coalescence based increase in mean particle size for the low surface area carbon nanotubes. In contrast, the highly microporous hollow carbons showed strongly enhanced particle stability where Ostwald ripening accounted for the observed coarsening. Altogether, our study provides new atom scale insights into Pt C fuel cell catalyst stability. Based on this study, supports of intermediate surface area provide the best compromise between activity and size stability, while highly graphitized or highly nanoporous supports are detrimenta

In Situ Study of Atomic Structure Transformations of Pt Ni Nanoparticle Catalysts during Electrochemical Potential Cycling

When exposed to corrosive anodic electrochemical environments, Pt alloy nanoparticles NPs undergo selective dissolution of the less noble component, resulting in catalytically active bimetallic Pt rich core shell structures. Structural evolution of PtNi6 and PtNi3 NP catalysts during their electrochemical activation and catalysis was studied by in situ anomalous small angle X ray scattering to obtain insight in element specific particle size evolution and time resolved insight in the intraparticle structure evolution. Ex situ high energy X ray diffraction coupled with pair distribution function analysis was employed to obtain detailed information on the atomic scale ordering, particle phases, structural coherence lengths, and particle segregation. Our studies reveal a spontaneous lectrochemically induced formation of PtNi particles of ordered Au3Cu type alloy structures from disordered alloy phases solid solutions concomitant with surface Ni dissolution, which is coupled to spontaneous residual Ni metal segregation during the activation of PtNi6. Pt enriched core shell structures were not formed using the studied Ni rich nanoparticle precursors. In contrast, disordered PtNi3 alloy nanoparticles lose Ni more rapidly, forming Pt enriched core shell structures with superior catalytic activity. Our X ray scattering results are confirmed by STEM EELS results on similar nanoparticle

Structure of dealloyed core-shell Pt bimetallic fuel cell electrocatalysts studied by real and reciprocal space methods

ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIET

<i>In Situ</i> Study of Atomic Structure Transformations of Pt–Ni Nanoparticle Catalysts during Electrochemical Potential Cycling

When exposed to corrosive anodic electrochemical environments, Pt alloy nanoparticles (NPs) undergo selective dissolution of the less noble component, resulting in catalytically active bimetallic Pt-rich core–shell structures. Structural evolution of PtNi₆ and PtNi₃ NP catalysts during their electrochemical activation and catalysis was studied by <i>in situ</i> anomalous small-angle X-ray scattering to obtain insight in element-specific particle size evolution and time-resolved insight in the intraparticle structure evolution. <i>Ex situ</i> high-energy X-ray diffraction coupled with pair distribution function analysis was employed to obtain detailed information on the atomic-scale ordering, particle phases, structural coherence lengths, and particle segregation. Our studies reveal a spontaneous electrochemically induced formation of PtNi particles of ordered Au₃Cu-type alloy structures from disordered alloy phases (solid solutions) concomitant with surface Ni dissolution, which is coupled to spontaneous residual Ni metal segregation during the activation of PtNi₆. Pt-enriched core–shell structures were not formed using the studied Ni-rich nanoparticle precursors. In contrast, disordered PtNi₃ alloy nanoparticles lose Ni more rapidly, forming Pt-enriched core–shell structures with superior catalytic activity. Our X-ray scattering results are confirmed by STEM/EELS results on similar nanoparticles