Pt/TiO2 Catalyzed Hydrogenation of Benzoic Acid with Unprecedented High Activity

Abstract The hydrogenation of benzoic acid (BA) to corresponding cyclohexanecarboxylic acid has important industry and academia significance, however, the electron deficient aromatic ring and the catalyst “poison” by carboxyl group make BA hydrogenation as one of the most challenging transformations. Herein, we found that Pt NPs deposited on TiO2 were very effective for BA hydrogenation with a record TOF of 4490 h− 1 under 80 oC and 50 bar H2 in hexane, one order higher than the reported results. DFT calculation showed that Pt NPs had a weaker interaction with BA than Ru and Pd NPs commonly used for BA hydrogenation, which improved the toxicity resistance of catalyst to BA. Pt/TiO2 catalysts with electron deficient and electron enriched Pt sites were successfully synthesized by modifying the electron transfer direction between Pt and TiO2. Isotopic experiments suggested the participation of dissociated H from carboxyl group in BA hydrogenation. Consequently, the electron deficient Pt sites with stronger adsorption of BA were more active than electron rich Pt sites in BA hydrogenation. In addition to BA, terephthalic acid, iso-phthalic acid, trimesic acid and other BA derivatives could also be efficiently converted to corresponding aromatic saturated products, demonstrating the wide substrate scope of Pt/TiO2.

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Hydrogenation of benzoic acid derivatives over Pt/TiO2 under mild conditions

Communications Chemistry ◽

10.1038/s42004-021-00489-z ◽

2021 ◽

Vol 4 (1) ◽

Author(s):

Miao Guo ◽

Xiangtao Kong ◽

Chunzhi Li ◽

Qihua Yang

Keyword(s):

Electron Transfer ◽

Benzoic Acid ◽

High Efficiency ◽

Carboxyl Groups ◽

Carboxyl Group ◽

Benzoic Acids ◽

Catalyst Poisoning ◽

Benzoic Acid Derivatives ◽

Mild Conditions ◽

Transfer Direction

AbstractHydrogenation of benzoic acid (BA) to cyclohexanecarboxylic acid (CCA) has important industrial and academic significance, however, the electron deficient aromatic ring and catalyst poisoning by carboxyl groups make BA hydrogenation a challenging transformation. Herein, we report that Pt/TiO2 is very effective for BA hydrogenation with, to our knowledge, a record TOF of 4490 h−1 at 80 °C and 50 bar H2, one order higher than previously reported results. Pt/TiO2 catalysts with electron-deficient and electron-enriched Pt sites are obtained by modifying the electron transfer direction between Pt and TiO2. Electron-deficient Pt sites interact with BA more strongly than electron-rich Pt sites, helping the dissociated H of the carboxyl group to participate in BA hydrogenation, thus enhancing its activity. The wide substrate scope, including bi- and tri-benzoic acids, further demonstrates the high efficiency of Pt/TiO2 for hydrogenation of BA derivatives.

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Some Decomposition Routes in the Mass Spectra of Aromatic Carboxylic Acids

Zeitschrift für Naturforschung A ◽

10.1515/zna-1965-0704 ◽

1965 ◽

Vol 20 (7) ◽

pp. 883-887 ◽

Cited By ~ 49

Author(s):

J. H. Beynon ◽

B. E. Job ◽

A. E. Williams

Keyword(s):

Carboxylic Acid ◽

Benzoic Acid ◽

Terephthalic Acid ◽

Phthalic Acid ◽

Mass Spectra ◽

Deuterium Atom ◽

Acid Group ◽

Isophthalic Acid ◽

Carboxylic Acid Group ◽

Hydrogen Atoms

The mass spectra of benzoic acid, phthalic acid, isophthalic acid and terephthalic acid, together with the analogues deuterated on the carboxylic acid group have been studied. Exchange of the deuterium atom with hydrogen atoms on the positions ortho to a carboxylic acid group on the aromatic ring has been studied using meta-stable peaks.

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Fluorescent Sensors For Hg2+ and Cu2+ Based On Condensation Products of 4H-1,2,4 Triazole-4-Amine And Carboxylated Benzoic Acids

10.21203/rs.3.rs-400901/v1 ◽

2021 ◽

Author(s):

Satyapriya Deka ◽

Ankur K Guha ◽

Diganta Kumar Das

Keyword(s):

Benzoic Acid ◽

Terephthalic Acid ◽

Phthalic Acid ◽

Copper Ion ◽

Binding Constants ◽

Isophthalic Acid ◽

Benzoic Acids ◽

Health Issues ◽

Derivatives Of ◽

Optimized Geometries

Abstract Mercury (Hg) causes serious health issues in its all forms. Deficiency as well as excess of copper ion (Cu2+) in human body is hazardous. A series of four compounds have been derived from carboxylated benzoic acids (benzoic acid, isophthalic acid, terephthalic acid and phthalic acid) and 4H-1,2,4 triazole-4-amine and characterized. Fluorescencce detection of Hg2+ was recorded by the derivates with benzoic acid and isophthalic acid while the derivatives of terephthalic acid and phthalic acid detect Cu2+ by fluorescence “off” mode. Metal ions like Li+, Na+, K+, Zn2+, Al3+, Mg2+, Mn2+, Co2+, Ni2+, Cu2+, Cd2+, Pb2+ and Hg2+ found not to interfere. The stoichiometry of binding is 1:1 for the benzoic acid derivative with Hg2+ while it is 1:2 for the other three derivatives. The binding constants are ca. 10− 4.5 between the sensors and Hg2+ or Cu2+ and detection limits are around 10− 5.5 M. DFT calculation provided optimized geometries of the sensors and confirmed the stoichiometry of binding with Hg2+/Cu2+.

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The modulation effect of carboxylic acid ligands on the electron transfer photochromism of naphthalene diimide-derived coordination polymers

Dalton Transactions ◽

10.1039/d1dt02358f ◽

2021 ◽

Author(s):

Gao-Peng Li ◽

Huihui Zhu ◽

Pengfei Hao ◽

Junju Shen ◽

Yunlong Fu

Keyword(s):

Electron Transfer ◽

Carboxylic Acid ◽

Coordination Polymers ◽

Terephthalic Acid ◽

Phthalic Acid ◽

Modulation Effect ◽

Naphthalene Diimide

Four naphthalene diimide (NDI)-derived coordination polymers (CPs), [Cd(3-DPNDI)(o-BDC)] (1), [Cd(3-DPNDI)2(p-BDC)(NO3)] (2), [Cd(3-DPNDI)(NDC)(H2O)2] (3), [Cd(3-DPNDI)(BPC)(H2O)] (4) (3-DPNDI = N,N'-di-(3-pyridyl)-1,4,5,8-naphthalene diimide，o-BDC = phthalic acid, p-BDC = terephthalic acid, NDC = 2,6-naphthalenedicarboxylic acid,...

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Studies on Sporopollenin Biosynthesis in Cucurbita maxima I: The Substantial Labeling of Sporopollenin from Cucurbita maxima after Application of [14C]Phenylalanine

Zeitschrift für Naturforschung C ◽

10.1515/znc-1993-1-203 ◽

1993 ◽

Vol 48 (1-2) ◽

pp. 10-15 ◽

Cited By ~ 7

Author(s):

Sabine Gubatz ◽

Rolf Wiermann

Keyword(s):

Terephthalic Acid ◽

Phthalic Acid ◽

Degradation Products ◽

Hydroxybenzoic Acid ◽

Cucurbita Maxima ◽

Purification Step ◽

Decanedioic Acid ◽

Octanedioic Acid ◽

High Level ◽

Tracer Experiments

The results of tracer experiments performed with anthers of Tulipa cv. Apeldoorn have already shown that a high level of incorporation into the sporopollenin fraction was achieved, when [14C]phenylalanine was applicated as a precursor. In order to investigate whether the substantial incorporation of [14C]phenylalanine is a unique phenomenon restricted to Tulipa, tracer experiments were carried out on anthers of Cucurbita maxima. The sporopollenin fraction was isolated and purified by a gentle method including extractions with various solvents, incubations with hydrolysing enzymes and fractionated saponifications. The remaining, as well as the released radioactivity, was determined after each purification step. After the application of [U-14C]phenylalanine, a substantial incorporation into the sporopollenin fraction was determined. The values were clearly higher than those obtained with [1-14C]glucose or those from corresponding experiments on Tulipa anthers. After potash fusion of sporopollenin fractions labeled via [U-14C]phenylalanine, p-hydroxybenzoic acid was shown to be the main com ponent among the ether soluble acids; moreover it showed the highest level of radioactivity. No radioactivity was detected in the degradation products oxalic acid, benzoic acid, phthalic acid and terephthalic acid or octanedioic acid- and decanedioic acid-dimethylester.

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