Operando and in situ Raman studies of alumina-supported vanadium phosphatecatalysts in propane ammoxidation reaction: activity, selectivity and active phase formation

文献情報

出版日 2011-10-12

DOI 10.1039/C1CP22608H

インパクトファクター 3.676

著者

Ewelina Mikolajska, Søren B. Rasmussen, Anna E. Lewandowska, Miguel A. Bañares

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要旨

Alumina-supported VPO materials are efficient catalysts for acrylonitrile production by the propane ammoxidation reaction. In order to understand the structure–activity relationship and the nature of active sites, operando Raman-GC analyses follow the states of vanadium and phosphorous species on an alumina support during ammoxidation. These oxides were supported on γ-alumina by incipient wetness impregnation at a total V + P loading of two monolayers, which led to incipient formation of nanoscaled VPO crystallites possessing a high surface-to-volume ratio. Since catalysis occurs at the catalyst surface, which is related to the surface and outermost layers, this approach allows studying surface species phase transformations near the surface, and relates changes in activity and selectivity to variations in composition and structure. Dispersed surface V5+ species appear selective to acetonitrile and V4+ species would promote selectivity to acrylonitrile. This study suggests that V3+ is probably involved in redox processes during propane ammoxidation and that the balance between these vanadium species would be determined by activation process.

掲載誌

Physical Chemistry Chemical Physics

CiteScore: 5.5

自己引用率: 10.3%

年間論文数: 3036

Physical Chemistry Chemical Physics (PCCP) is an international journal co-owned by 19 physical chemistry and physics societies from around the world. This journal publishes original, cutting-edge research in physical chemistry, chemical physics and biophysical chemistry. To be suitable for publication in PCCP, articles must include significant innovation and/or insight into physical chemistry; this is the most important criterion that reviewers and Editors will judge against when evaluating submissions. The journal has a broad scope and welcomes contributions spanning experiment, theory, computation and data science. Topical coverage includes spectroscopy, dynamics, kinetics, statistical mechanics, thermodynamics, electrochemistry, catalysis, surface science, quantum mechanics, quantum computing and machine learning. Interdisciplinary research areas such as polymers and soft matter, materials, nanoscience, energy, surfaces/interfaces, and biophysical chemistry are welcomed if they demonstrate significant innovation and/or insight into physical chemistry. Joined experimental/theoretical studies are particularly appreciated when complementary and based on up-to-date approaches.