Support Morphology Effect on Selective Hydrogenation of 3‐Nitrostyrene to 3‐Vinylaniline over Pt/α‐Fe₂O₃ Catalysts

Abstract

Selective hydrogenation of substituted nitroaromatic compounds is an extremely important and challenging reaction. Supported metal catalysts attract much attention in this reaction because the properties of metal nanoparticles (NPs) can be modified by the nature of the support. Herein, the support morphology on the catalytic performance of selective hydrogenation of 3‐nitrostyrene to 3‐vinylaniline was investigated. Pt NPs supported on octadecahedral α‐Fe2O3 supports with a truncated hexagonal bipyramid shape (Pt/α‐Fe2O3‐O) and rod‐shaped α‐Fe2O3 supports (Pt/α‐Fe2O3‐R) were prepared by glycol reduction method. Detailed characterizations reveal that the electronic structure and dispersion of Pt NPs can be modified by the supports. The Pt/α‐Fe2O3‐O catalyst exhibited superior catalytic performance for hydrogenation of 3‐nitrostyrene because of its low coordinated Pt sites and the small Pt NPs size, which is benefit from the high‐index exposed surfaces of truncated hexagonal bipyramid‐shaped α‐Fe2O3 support. The structural evolution during the catalytic reaction was investigated in detail by identical location transmission electron microscopy (IL‐TEM) method, which found that the high cycling activity of Pt/α‐Fe2O3‐O catalyst during the cycle experiment results from the stability of Pt NPs.

Structural Regulation of PtCo/Y Zeolite Catalysts for the Selective Hydrogenation of 3-Nitrostyrene to 3-Vinylaniline

“…3,5−7 Catalytic hydrogenation of nitroarenes using molecular H 2 is highly desirable for the production of functionalized anilines with regard to a clean, economic, and efficient production process. 8,9 In practice, however, achieving high selectivity to target products still remains a challenge in this reaction without the addition of any homogeneous additives. 8 In the hydrogenation of nitroarenes, platinum (Pt)-based catalysts possess high catalytic activity, but they are more productive for the vinyl group in the hydrogenation of nitrostyrene (NS), resulting in low selectivity to aminostyrene (AS).…”

“…Functionalized anilines are important intermediates with high synthetic value. , They are commonly used in the production of a lot of fine and bulk chemicals, including fertilizers, pharmaceuticals, polymers, dyes, and biologically active compounds. , Although many stoichiometric reducing agents (such as sodium hydrosulfite, stannous chloride, etc.) are still used widely to reduce nitroaromatics [e.g., 3-nitrostyrene (3-NS)], they not only are unselective but also lead to serious environmental issues. ,− Catalytic hydrogenation of nitroarenes using molecular H 2 is highly desirable for the production of functionalized anilines with regard to a clean, economic, and efficient production process. , In practice, however, achieving high selectivity to target products still remains a challenge in this reaction without the addition of any homogeneous additives …”