Phosphorus-Doped Activated Coconut Shell Carbon-Anchored Highly Dispersed Pt for the Chemoselective Hydrogenation of Nitrobenzene to p-Aminophenol

Abstract

Highly dispersed Pt nanoparticles (∼2.5 nm) on phosphorus-doped activated coconut shell carbon (Pt/P-ACC) were synthesized by a two-step impregnation route. Pt/P-ACC showed a high activity, chemoselectivity, and reusability toward the hydrogenation of nitrobenzene to p -aminophenol, with hydrogen as the reducing agent in sulfuric acid. The effects of P species on the catalyst structure, surface properties, and catalytic performance were investigated. It was found that the Pt/P-ACC catalyst had an excellent catalytic activity due to its smaller Pt nanoparticles and higher content of surface-active metal compared with Pt/ACC. Besides, the experimental results and in situ infrared studies demonstrated that the interaction effect between the Pt and P species imbued the surface of Pt with an electron-rich feature, which decreased the adsorption of electron-rich substrates (that is, phenylhydroxylamine) and prevented their full hydrogenation, leading to enhanced selectivity during the hydrogenation of nitrobenzene to p -aminophenol.

Origin of the synergistic effects of bimetallic nanoparticles coupled with a metal oxide heterostructure for accelerating catalytic performance

“…These results confirm the strong electronic interactions between PtRuP and the NiO@TiO x support. A comparison of the conversion and selectivity of dissimilar catalysts (Figure 3F) showed that us‐PtRuPNiNiO@TiO x has the highest catalytic efficiency among the reported Pt‐based catalysts 22–27 …”

“…A comparison of the conversion and selectivity of dissimilar catalysts (Figure 3F) showed that us-PtRuPNiNiO@TiO x has the highest catalytic efficiency among the reported Pt-based catalysts. [22][23][24][25][26][27]…”

Selective Hydrogenation of Nitrobenzene to para-Aminophenol on a Zirconium-Phosphate-Supported Platinum Catalyst

“…The intermediate PHA can be converted into PAP by acid-catalyzed Bamberger rearrangement, − and thus, the influence of acid concentration on the selectivity of PAP was examined. As shown in Figure d, the acid concentration ranged from 0 to 1.13 M under the standard reaction conditions.…”

“…para -Aminophenol (PAP) is a key raw material in chemical industry, which is widely used in the fields of photosensitive materials, medicine, dyes, pesticides, and rubber. − Traditionally, the industrial production process of PAP involves starting from raw materials such as phenol, p -nitrophenol, − p -nitrochlorobenzene, and nitrobenzene (NB). − Among them, the iron powder reduction method using p -nitrophenol as raw material is the earliest route for producing PAP. However, this method inevitably produces a large amount of wastewater and iron sludge with high cost and serious pollution and is rarely used now.…”

Gemini surfactant‐stabilized Pd nanoparticles: Synthesis, characterization, and catalytic application in the reduction and reductive acetylation in the water solvent

“…50 Moreover, being stabilized by positively charged L4, these small sized Pd NPs offers a large and suitable surface for long range (CH 3 ) 2 N + -----À O-N + (-Ph-R)=O interaction. 51 Sodium borohydride as a reductant release H 2 on the surface of Pd NPs without affecting it and also provide the necessary basic pH for the reaction. 52 The released H 2 and nitro-aromatics altogether get facilitated to react over the surface of Pd-L4 NPs through the reaction, that is, S C H E M E 3 Pd-L4 NPs catalyzed reduction of nitro-aromatic compounds in the presence of other reducible groups.…”