Synthesis of nanoparticle-built FeVO4 microspheres with improved low temperature catalytic activity in ammoxidation

Li, Xiongjian; Hu, Hao; Chen, Piao; Chen, Fang; Shui-jin, Yang

doi:10.1016/j.cplett.2021.139107

Cited by 4 publications

(1 citation statement)

References 30 publications

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“…As an important type of intermediates for organic reactions [1,2], aromatic nitriles are widely used in dyes, medicine, pesticides, perfumes and plastics industries [3,4], and the demand for various aromatic nitriles has increased year by year in the international market. Many methods have been developed to prepare aromatic nitriles over the past 100 years , among which direct ammoxidation of methyl aromatics is the most economical and environmentally friendly method and is widely used for the production of aromatic nitriles in industry [21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37]. The ammoxidation catalyst plays a key role in the synthesis of aromatic nitriles through ammoxidation of substituted toluenes and methyl heteroaromatics.…”

Section: Introductionmentioning

confidence: 99%

Spray dried VCrO/SiO2 micro-spheroidal catalyst for the ammoxidation of p-chlorotoluene

Du,

Huang,

Tang

et al. 2023

Res Chem Intermed

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Formulation and shaping of heterogeneous catalysts are vital in the successful industrial application. Here micro-sized vanadium chromium composite oxides catalysts with the spherical shape were prepared via spray drying with colloidal silica as a binder material. The structural properties of catalysts with different Cr/V molar ratios were characterized by XRD, XPS, FT-IR, TPR, and particle size distribution analysis. It was revealed that the addition of Cr inhibited the formation of the crystalline phase V2O5 and decreased the reduction temperature of pentavalent vanadium species, and also resulted in the formation of monoclinic CrVO4 and a highly dispersed state of vanadia species. VCrO/SiO2 particles with various Cr/V atomic ratio were studied as catalysts for p-chlorotoluene ammoxidation to p-chlorobenzonitrile, in which the catalyst with Cr/V ratio of 1 exhibited the best catalytic performance. When the Cr/V ratio was less than 1, mixed phases of orthorhombic CrVO4 and monoclinic Cr2V4O13 were formed and resulted in a low catalytic activity. With the increase of Cr/V ratio, the ratio of V 4+ /V 5+ in the catalysts increased, thus the activation energy required for V reduction decreased, resulting in the catalytic activity of the catalysts improved. However, too large an amount of Cr led to the formation of highly oxidizing hexagonal-Cr2O3 phase, which reduced the selectivity of the catalytic reaction.

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