Journal ArticleDOI
Synthesis of p-aminophenol from the hydrogenation of nitrobenzene over metal-solid acid bifunctional catalyst
TLDR
In this paper, S2O82−/ZrO2 (PSZ) solid acid and Pt-S 2O82 −/ZRO2 bifunctional catalysts were prepared for the synthesis of p-aminophenol (PAP) in non-acid medium.Abstract:
BACKGROUND: A single-step conversion of nitrobenzene (NB) to p-aminophenol (PAP) through catalytic hydrogenation is a widely used synthesis route for PAP The main shortcoming of this route is the use of sulfuric acid for rearrangement of the phenylhydroxylamine (PHA) intermediate In this paper, S2O82−/ZrO2 (PSZ) solid acid and Pt-S2O82−/ZrO2 (Pt-PSZ) bifunctional catalysts were prepared for the synthesis of PAP in non-acid medium
RESULTS: Calcination temperature has a substantial effect on the acidity, structure and activity for PHA rearrangement of PSZ The highest PAP yield was 338% over PSZ calcined at 823 K when the reaction was carried out in water at 423 K A high PAP yield of 239% was achieved by a single-step reaction of nitrobenzene over Pt-PSZ bifunctional catalysts
CONCLUSION: PSZ solid acid exhibits high activity for PHA rearrangement Perfect tetragonal ZrO2 and much stronger acid sites play important roles in catalytic activity Inhibiting the hydrogenation activity by reducing the amount of Pt loading on Pt-PSZ can improve the competition of PHA rearrangement on acid sites with hydrogenation of PHA on metal active sites, resulting in better selectivity to PAP Copyright © 2008 Society of Chemical Industryread more
Citations
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Journal ArticleDOI
Acid-Resistant Catalysis without Use of Noble Metals: Carbon Nitride with Underlying Nickel
TL;DR: In this paper, a nanocomposite able to function as a hydrogenation catalyst under strongly acidic conditions without the presence of noble metals is synthesized and thoroughly studied, which possesses a unique structure composed of carbon nitride (CN) with underlying nickel, in which the nickel endows the CN with new active sites for hydrogen adsorption and activation while it itself is physically isolated from the reactive environment.
Journal ArticleDOI
Heterogeneous Bifunctional Metal/Acid Catalysts for Selective Chemical Processes
TL;DR: In this paper, the most representative examples and the recent achievements in the field of solid bifunctional metal/acid-site catalysts and their application to the production of fine chemicals through selective, cooperative, or sequential processes in single reactor units are reviewed.
Journal ArticleDOI
Controlled synthesis of Pd–NiO@SiO2 mesoporous core–shell nanoparticles and their enhanced catalytic performance for p-chloronitrobenzene hydrogenation with H2
TL;DR: In this article, a mesoporous PdNiO@SiO2 core-shell nanocatalysts were successfully synthesized by a sol-gel method, and the characterization results by XRD, TEM and BET revealed that Pd−NiO+SiO+NiOµµ was highly stable with the maintenance of intact core−shell structures under high-temperature thermal treatments.
Journal ArticleDOI
Amidation of phenol derivatives: a direct synthesis of paracetamol (acetaminophen) from hydroquinone
TL;DR: In this paper, a direct synthesis of paracetamol from hydroquinone using ammonium acetate as an amidating agent has been developed with high yield and selectivity (>95%).
Journal ArticleDOI
Development of nickel-incorporated MCM-41–carbon composites and their application in nitrophenol reduction
TL;DR: In this article, a soft-templating strategy was used to obtain the Ni-containing MCM-41-carbon composites using nickel nitrate as an additive, which showed enhanced catalytic activity toward nitrophenol reduction obeying the zero-order kinetics.
References
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Sulfated zirconia and its modified versions as promising catalysts for industrial processes
Ganapati D. Yadav,Jayesh J. Nair +1 more
TL;DR: In this article, the chemistry and engineering aspects of sulfated zirconia catalyst and its modified forms are discussed, and the surface properties of these catalysts can be further modified in conjunction with noble or transition metals as promoters as well as with carbon molecular sieves.
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Sulfated Zirconia-Based Strong Solid-Acid Catalysts: Recent Progress
Xuemin Song,Abdelhamid Sayari +1 more
TL;DR: In this paper, a review article deals with recent progress in the preparation of sulfated zirconia (SZ)-bassed, strong solid-acid catalysts, the characterization of their physicochemical properties and the evaluation of their catalytic performance in various promising applications.
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Mechanism of acidity generation on sulfur-promoted metal oxides
TL;DR: The effect of sulfur promotion on the generation of strong acidity on ZrO/sub 2, TiO/Sub 2, Fe/sub O/sub 3, Al/sub S 2 O/S 3, SnO/S 2, and Bi O/O/3 was examined by the isomerization of cyclopropane and by infrared spectroscopy as discussed by the authors.
Journal ArticleDOI
Preparation of superacids by metal oxides for reactions of butanes and pentanes
TL;DR: In this article, the preparation of solid superacid catalysts which are active for reactions of butanes and pentanes is reviewed, and metal-promoted superacids which are highly active for the reaction of butane to isobutane are prepared by addition of salts of Pt, Ir, Rh, Ru, Os, Pd, Fe, and Mn (equivalent to Pt of 7.5 wt%) to sulfated zirconia gel followed by calcination.
Journal ArticleDOI
Synthesis of p-Aminophenol by Catalytic Hydrogenation of Nitrobenzene
TL;DR: In this paper, a single-step catalytic hydrogenation of nitrobenzene in acid medium is described, which achieves selectivity to p-aminophenol as high as 75% under the best set of conditions.
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