Showing papers on "Benzoic acid published in 2019"
TL;DR: In this article, a model of BiOCl with tailored facets was designed as a model photocatalyst to clarify the mechanism of photocatalytic toluene degradation, and the theoretical calculations and in situ DRIFTS technology were closely combined to dynamically predict and monitor the photocatally-driven degradation reactions.
Abstract: The ring-opening process is the rate-determining step for photocatalytic decomposition of aromatic volatile organic compounds (VOCs). However, the ring-opening pathway has not been fully revealed, which enables efficient photocatalytic VOC degradation. Taking the photocatalytic toluene degradation as a typical case, the ring-opening pathway and regulation strategy were systematically investigated and proposed with an aim to regulate the rate-determining step and accelerate the reaction rates. Herein, BiOCl with tailored facets was designed as a model photocatalyst to clarify the mechanism of photocatalytic toluene degradation. Theoretical calculations and in situ DRIFTS technology were closely combined to dynamically predict and monitor the photocatalytic toluene degradation reactions. It is revealed that the lowest energy barrier was precisely located at the ring-opening of benzoic acid which was generated from toluene oxidation. This result implied that the benzyl must be fully oxidized to benzoic acid to elevate the ring-opening reaction rates. Moreover, the alternative charge arrangement on the {010} facet of BiOCl facilitated the benzyl oxidation and selectivity for benzoic acid ring-opening reactions, subsequently resulting in remarkably enhanced photocatalytic efficiency, exceeding that of the {001} facet by 100% towards toluene decomposition. This work demonstrates that probing and tailoring the ring-opening pathway are vital to increase the overall toluene decomposition efficiency and could provide new insights into the understanding of the photocatalytic reactions in VOC degradation.
156 citations
TL;DR: In this paper, the linkers of benzoic acid (BA), 1,4-benzene dicarboxylic acid (DDA), and 1,3,5-benzenetricarboxyl acid (BTC) were used to synthesize lanthanum organic frameworks.
Abstract: In this study, we tried to synthesize lanthanum organic frameworks (MOFs) with the linkers of benzoic acid (BA), 1,4-benzene dicarboxylic acid, and 1,3,5-benzenetricarboxylic acid (BTC), abbreviate...
96 citations
TL;DR: In this article, the photocatalytic behaviors of BiOCl and TiO2 for the degradation of different pollutants including perfluorooctanoic acid (PFOA), chloroacetic acids and benzoic acid were compared.
Abstract: Although all the semiconductor-based photocatalysis is initiated by photoinduced conduction band electron and valence band hole, the reaction pathway and activity of the electron and hole would be largely dependent on the type of the photocatalyst. It is essential to distinguish and understand the photocatalyst-dependence of a specific reaction. In the present study, we compared the photocatalytic behaviors of BiOCl and TiO2 for the degradation of different pollutants including perfluorooctanoic acid (PFOA), chloroacetic acids and benzoic acid. We found that the decompositions of perhalocarboxylate acids (PHCAs) such as PFOA and trichloroacetic acid (TCA) were much rapider over BiOCl than on the TiO2 (commercial P25). The surface-area- normalized rate constants for the oxidation of TCA have five orders of magnitude of difference between these two systems. By contrast, the degradation rates of OH-sensitive organic pollutants such as dichloroacetic acid, monochloroacetic acid and benzoic acid were much higher on the TiO2. Moreover, much more meta-substituted hydroxylated intermediate was observed during the photocatalytic oxidation of benzoic acid on BiOCl. In addition, PFOA and TCA were degraded efficiently in the BiOCl system even in the presence of other labile organic compounds (such as acetic acid). All the experimental results definitely indicate that BiOCl photocatalyst prefers to directly oxidize the PHCAs and benzoic acid by the hole transfer, while TiO2 tends to oxidize the solvent water molecule to OH radical. The mechanism underlying on the different activity of BiOCl and TiO2 are further discussed.
87 citations
TL;DR: In this paper, the photocatalytic performance of a thermally exfoliated carbon nitride material was investigated in aqueous solution and employing visible-light emitting diodes (LEDs) as radiation source.
Abstract: The photocatalytic performance of a thermally exfoliated carbon nitride material was investigated in aqueous solution and employing visible-light emitting diodes (LEDs) as radiation source (λmax = 417 nm). The operating conditions were studied using phenol as model compound. The increase on the surface area of the catalyst with the exfoliation treatment promotes faster degradation and mineralization rates and an easier reduction of O2 into H2O2. The H2O2 production takes place only in the presence of both phenol and dissolved oxygen. The study was followed by assessing the photocatalytic degradation of ten organic compounds (individually or in a mixture) commonly found in agro-industrial wastewaters (phenol, catechol, resorcinol, hydroquinone, benzoic acid, 4-hydroxybenzoic acid, protocatechuic acid, gallic acid, 4-methoxyphenol and tyrosol). These compounds were selected to study the position, order and nature of substitution on the aromatic ring as well as the possible influence of the pKa. Generally, more reactive compounds yield higher amounts of H2O2 formed, whereas the pKa does not affect photocatalysis owing to the amphoteric properties of the catalyst. Thus, the successful oxidation of the organic compounds achieved in situ generation of H2O2 with relatively high productivities using a metal-free carbon nitride material stable in consecutive runs.
70 citations
TL;DR: A good antibacterial, antioxidant and antitumor activity in the nanoparticles synthesized using 4-N-methyl benzoic acid derived from a medicinal plant can be further tested to formulate a good lead compound for biomedical applications.
62 citations
TL;DR: In this article, the acid-base properties of AMO-LDH-based oxide catalysts with various ratios of Mg/Al were studied for the chemical and physical properties and the activity on esterification of benzoic acid with 2-ethylhexanol.
Abstract: Proven to possess distinguishable physical and acid-base properties superior to conventional LDHs, Aqueous Miscible Organic solvent-Layered Double Hydroxides (AMO-LDHs) were thus synthesized and used as precursors to prepare the Mg/Al mixed oxide catalysts in this work. The AMO-LDH based oxide catalysts with various ratios of Mg/Al were studied for the chemical and physical properties and the activity on esterification of benzoic acid with 2-ethylhexanol. The catalysts were characterized using BET, XRD, TGA, and XPS. Moreover, the acid-base properties were studied by using NH3-TPD, CO2-TPD, and X-ray Absorption Spectroscopy (XAS) techniques, both XANES and EXAFS. As a result, the Mg/Al mixed oxides after calcination at 500 °C still had the clay structure, and were found to possess both acid and base sites. As the Mg/Al ratio increased, the total density of acid and basic sites decreased. Moreover, the acid-basic strength depended on their phase compositions and coordination number. The activity of calcined LDHs catalysts was tested for the esterification of benzoic acid with 2-ethylhexanol, aimed at producing 2-ethylhexyl benzoate as the desired chemical. The products were analyzed using GC–MS/TOF. In summary, the conversion of benzoic acid was enhanced significantly using the Mg Al mixed oxides as the catalysts, owing to the acid-base sites (both Mg2+ O2− and Al3+ O2− pairs) of the catalysts. The catalyst with the Mg/Al ratio of 4:1 can convert 66% benzoic acid to 2-ethylhexyl benzoate. Moreover, the other products were composed of 2-ethylhexanal, 3-heptanone, and 3-heptanol because of acid-base pairs.
61 citations
TL;DR: Density functional theory calculations support the unprecedented role of halides as active Lewis base components in the frustrated Lewis pair mediated hydrogen activation in theMetal-free reduction of carboxylic amides using oxalyl chloride as an activating agent and hydrogen as the final reductant.
Abstract: A method for the metal-free reduction of carboxylic amides using oxalyl chloride as an activating agent and hydrogen as the final reductant is introduced. The reaction proceeds via the hydrogen splitting by B(2,6-F2-C6H3)3 in combination with chloride as the Lewis base. Density functional theory calculations support the unprecedented role of halides as active Lewis base components in the frustrated Lewis pair mediated hydrogen activation. The reaction displays broad substrate scope for tertiary benzoic acid amides and α-branched carboxamides.
61 citations
TL;DR: In this article, tunable holes and vacancies in nickel hydroxide (h-Ni(OH)2) by the Ostwald ripening process are successfully fabricated, and the as-prepared electrocatalysts are used for the selective ECO of alcohols into acids or aldehydes with excellent electrocatalysis activity and stability.
59 citations
TL;DR: In this paper, a binary W18O49/holey ultrathin g-C3N4 nanosheets (HU-CNS) was prepared via a solvothermal method and it exhibited excellent photocatalytic activity for the selective oxidation of benzyl alcohol in an aqueous medium under room temperature and atmospheric pressure.
Abstract: Synthesis of intermediates and fine chemicals for the selective oxidation of alcohols to corresponding aldehydes and carboxylic acid is an extremely significant chemical reaction. Herein, a binary W18O49/holey ultrathin g-C3N4 nanosheets (HU-CNS) nanocomposite was prepared via a solvothermal method and it exhibited excellent photocatalytic activity for the selective oxidation of benzyl alcohol in an aqueous medium under room temperature and atmospheric pressure. The as-synthesized W18O49/HU-CNS composites showed higher selectivity and conversion efficiency compared to pure g-C3N4, which was mainly ascribed to the moderate adsorption capacity of benzaldehyde on the composite. The high conversion originates primarily from the following: (1) the W18O49/HU-CNS nanocomposite possessing a stronger ability to chemisorb alcohol than g-C3N4; (2) the oxygen vacancies on W18O49 nanowires not only supplied active centers for the activation of O2 to O2•– but also extended the range of light response from the visible t...
58 citations
TL;DR: In this paper, the authors investigated the oxidation capacity and mechanisms involved in activation of peroxomonosulfate (PMS) by nanoscale zero valent tungsten (nZVW) with dimethyl phthalate (DMP) as a targeted contaminant.
49 citations
TL;DR: In this article, the slow pyrolysis of polyethylene terephthalate (PET) was investigated over a range of final temperatures from 410°C to 480°C yielding a wide variety of species.
TL;DR: Subnanocatalysts containing various noble metals with sizes of approximately 1 nm were synthesized using dendritic poly(phenylazomethine)s as a macromolecular template, resulting in the formation of valuable organic products, including benzoic acid as the major product.
Abstract: Subnanocatalysts (SNCs) containing various noble metals (Cu, Ru, Rh, Pd, or Pt) with sizes of approximately 1 nm were synthesized using dendritic poly(phenylazomethine)s as a macromolecular template. These materials exhibit high catalytic performance during toluene oxidation without the use of harmful solvents or explosive oxidants, resulting in the formation of valuable organic products, including benzoic acid as the major product. In particular, Pt19 SNC with a narrow particle size distribution exhibits extraordinary catalytic activity, with a turnover frequency of 3238 atom-1 h-1 , which is 1700 times greater than that obtained by commercial Pt/C catalysts.
TL;DR: A new efficient synthetic method towards the elusive MIL-88B(Cr), yet reported only once without synthetic details, is proposed and has an interesting and potentially valuable property of retaining its high-volume form after thermal activation.
Abstract: The concentration of benzoic acid was found to exercise efficient control over the formation of either MIL-101(Cr) or MIL-88B(Cr) under otherwise similar hydrothermal synthetic conditions. Nanocrystals of MIL-101(Cr) with ∼100 nm average size and excellent SBET = 3467 m2 g−1 are obtained at lower concentrations of benzoic acid, while at higher concentrations the microparticulated MIL-88B(Cr) product is formed. Hereby a new efficient synthetic method towards the elusive MIL-88B(Cr), yet reported only once without synthetic details, is proposed. The obtained MIL-88B(Cr) has an interesting and potentially valuable property of retaining its high-volume form (Vcell ∼ 2000 A3) after thermal activation. The degassing of MIL-88B(Cr) in a vacuum at 250 °C yields a porous material with a SBET area of 1136 m2 g−1, which is around the theoretical maximum. The transition to the denser ‘closed’ form (Vcell ∼ 1500 A3) occurs only at 350 °C, when all of the benzoate/benzoic acid, hindering the process, is removed.
TL;DR: In this article, a new and cost-effective NiMgAl mixed metal oxide (Ni2Mg0.5Al1-MMO) catalyst derived from hierarchical flower-like Ni-Mg-Al layered double hydroxides was fabricated by a hydrothermal-calcination-reduction method.
TL;DR: Nickel-catalyzed decarbonylation of N-acylated N-heteroarenes is developed, allowing aromatic acids to serve as an aryl source in arylation of NH-heterOarenes.
Abstract: Nickel-catalyzed decarbonylation of N-acylated N-heteroarenes is developed. This method can be used to produce a variety of N-aryl heteroarenes, including pyrroles, indoles, carbazoles and phenoxazines, using benzoic acid derivatives as arylating reagents. Arylnickelamide intermediates that are relevant to the catalytic reaction were characterized by X-ray crystallography. When N-acylated benzimidazoles are used as substrates, decarbonylation accompanied 1,2-migration to form 2-arylated benzimidazoles.
TL;DR: In this article, a mechanism pathway was proposed based on the in-situ DRIFTS results, where the initial step was the adsorption of toluene on catalyst, then the benzoic acid was rapidly converted to phenol and maleate in the presence of O2, and the intermediates were further oxidized to CO2 and H2O by reacting with the supplementary surface lattice oxygen.
TL;DR: In this paper, two aromatic carboxylic acids (benzoic acid and isophthalic acid) are proposed to modify the permeability of poly(amide-b-ethylene oxide) or Pebax for CO2 separation membranes.
TL;DR: It is assumed that X2/HOX, rather than halogen radicals, is responsible for the enhanced formation of organohalogens in the heat/persulfate (PS) system and these findings are meaningful to evaluate the PS-based technologies for the high-salinity wastewater and to develop useful strategies for mitigating the negative effects of halides in advanced oxidation processes (AOPs).
TL;DR: UV-Vis limit of detection data for fluoride, acetate, and phosphate, support that HABA can detect low concentration of these anions, and 1H NMR titrations data confirmed association constants values in agreement with those of UV-Vis, besides showing evidence of the analyte interaction by the hydrogen-bonding of the carboxylic acid group.
TL;DR: A cost-effective method for the selective oxidation of toluene to benzaldehyde was developed based on immobilized CoOx on SiO2 catalyst with predominating cobaltous ions in the presence of N-hydroxyphthalimide (NHPI) and hexafluoropropan-2-ol (HFIP) using ambient molecular oxygen at room temperature.
TL;DR: Benzoic acid (BA), a naturally occurring, cheap, readily recyclable, and thermally stable weak acid, is shown to trigger the organocatalyzed ring-opening copolymerization (OROcP) of l-LA and CL under solvent-free conditions at 155 °C, in presence of various alcohols as initiators, with good control over molar masses and dispersities.
TL;DR: In this paper, CoPyds bearing three 4-pyridines and one benzoic acid as meso-position substituents are adopted as photosensitizer of Pt-loaded carbon nitride (C3N4) for visible-light-responsive H2 production.
TL;DR: In this article, single crystal CPO-27-Mg, -Zn and its structural isomer UTSA-74 have been prepared through use of acid modulators; salicylic acid and benzoic acid, respectively.
Abstract: Single crystal CPO-27-Mg, -Zn and its structural isomer UTSA-74 have been prepared through use of acid modulators; salicylic acid and benzoic acid, respectively. Salicylic acid directed the synthesis of CPO-27-Mg/Zn whereas benzoic acid the synthesis of UTSA-74. Through “in-house” SCXRD, DMF was seen to bind to the Zn2+ and water to the Mg2+ metal sites in CPO-27-M. Although the synthesis conditions were analogous for UTSA-74, DMF is too large to bind due to the proximity of the binding sites. A dissolution–recrystallisation transformation was examined from UTSA-74 to CPO-27-Zn. The release of nitric oxide was measured for each material.
TL;DR: In this article, a metal-organic framework (MOF) with a Zr(IV) ion containing a 2,3,5,6-tetrakis(4-carboxyphenyl)pyrazine (H4L) ligand was prepared by a solvothermal method.
Abstract: A metal–organic framework (MOF) with a Zr(IV) ion containing a 2,3,5,6-tetrakis(4-carboxyphenyl)pyrazine (H4L) ligand was prepared by a solvothermal method. ZrOCl2·8H2O was employed along with the H4L ligand and benzoic acid (modulator) in N,N-dimethylformamide (DMF) to synthesize the title compound. The as-synthesized compound has the formula [Zr6(μ3-O)4(μ3-OH)4(OH)4(H2O)4(L)2]·3H2O·2DMF (1). The activation of 1 was carried out by using methanol exchange and subsequent heating under high vacuum at 130 °C. Both 1 and the activated sample (1′) were characterized by X-ray powder diffraction (PXRD), Fourier transform infrared (FT-IR) spectroscopy and thermogravimetric analysis (TGA). They displayed high chemical stability and thermal stability. Both 1 and 1′ are stable up to 440 °C. Compound 1′ has a very high BET surface area (1419 m2 g−E) and CO2 adsorption capacity (4.4 mmol g−1 at 1.4 bar and 0 °C). Being highly water-stable, luminescent 1′ can selectively recognize Fe3+ and dichromate (Cr2O72−) in water and picric acid (PA) in dimethyl sulfoxide (DMSO), by a fluorescence quenching mechanism. The detection limits were found to be 3.75, 13.08 and 8.58 ppb for Fe3+, PA and Cr2O72−, respectively. Moreover, the mechanisms behind this selective detection of all three analytes were also investigated. In all three cases, the compound showed reusability up to five cycles without any loss of sensing efficacy. These experimental data vividly show that 1′ can be considered as a promising sensing material for Fe3+, PA and Cr2O72−.
01 Jan 2019
TL;DR: In this article, a series of complexes with Co(II), Ni(II, Cu(II) and Zn(II ) metal ions based on these ligands, have been synthesized and characterized through elemental analyses, FT-IR, NMR, UV/vis and mass spectroscopy.
Abstract: A couple of benzothiazole-imino-benzoic acid Schiff Bases namely (E)-2-((benzo[d]thiazol-2-ylimino)methyl)benzoic acid and (E)-2-(((5nitrobenzo[d]thiazol-2-yl)imino)methyl)-benzoic acid, derived from amino-benzothiazole, 2-formylbenzoic acid. A series of complexes with Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) metal ions based on these ligands, have been synthesized and characterized through elemental analyses, FT-IR, NMR, UV/vis and mass spectroscopy. The preparation of ligands as well as their metal complexes has been accomplished under mild conditions with reasonably good to high yields. These complexes are obtained through complete precipitation which led to their easy separation and optimum purity. Both the ligands and complexes show good antimicrobial activity against human epidemic causing bacterial strains (1143) which causes infection in mouth, lungs breast, gastrointestinal tract (4300) and nosocomial infections (741).
TL;DR: In this article, the solubility of benzamide in all solvents increases with the increase of temperature from 283.15 to 323.15 K, and generally depends on Solvents in the following order: methanol, methyl acetate, ethyl acetate and ethanol.
TL;DR: Steady-state adsorption studies showed that the resultant MMIRs had specific recognition for benzoic acids, GA, protocatechuic acid (PCA), vanillic Acid (VA), 4-hydroxybenzoicacid (4-HBA), salicylic acid (SA), and benzoIC acid (BA), which was promising for detection of benzoal acids in real aqueous samples.
TL;DR: In this article, nano-scale LiFePO4/C composite was prepared by adding monocarboxylic acid (benzoic acid), dicarboxyl acid (oxalic acid) and tricaroxylic acids (citric acid) as additives in ethylene glycol.
TL;DR: Irradiation of a series of p-substituted aryl benzoates under N2 atmosphere in homogeneous and micellar media was investigated by means of steady-state condition and of time-resolved spectroscopy and a notable selectivity in favor of the 2-hydroxybenzophenone derivatives was observed in miceLLar media.
Abstract: Irradiation of a series of p-substituted aryl benzoates under N2 atmosphere in homogeneous and micellar media was investigated by means of steady-state condition and of time-resolved spectroscopy. A notable selectivity in favor of the 2-hydroxybenzophenone derivatives was observed in micellar media. The benzophenone derivatives were the main photoproduct. On the other hand, in homogeneous media (cyclohexane, acetonitrile, and methanol) the observed product distribution was entirely different, viz. substituted 2-hydroxybenzophenones, p-substituted phenols, benzyl and benzoic acid were found. The binding constants in the surfactant were also measured and NOESY experiments showed that the aryl benzoates were located in the hydrophobic core of the micelle. Laser flash photolysis experiments led to the characterization of both p-substituted phenoxy radical and substituted 2-benzoylcyclohexadienone transients in homogeneous and micellar environment.
TL;DR: In this paper, the metal-support interfacial structure and catalyst basicity were modulated by changing the Mg/Al molar ratio of the hydrotalcite precursor, and the optimal performance was achieved on re-Mg6Al1-LDH-Pt with a GLY conversion of 87.6% and a GLYA yield of 58.6%, which exceeded the traditional activated carbon and oxide supports.
Abstract: Glycerol (GLY) aerobic oxidation in an aqueous solution is one of the most prospective pathways in biomass transformation, where the supported catalysts based on noble metals (mainly Au, Pd, Pt) are most commonly employed. Herein, Pt nanoparticles supported on rehydrated MgxAl1-hydrotalcite (denoted as re-MgxAl1-LDH-Pt) were prepared via impregnation-reduction method followed by an in situ rehydration process, which showed high activity and selectivity towards GLY oxidation to produce glyceric acid (GLYA) at room temperature. The metal-support interfacial structure and catalyst basicity were modulated by changing the Mg/Al molar ratio of the hydrotalcite precursor, and the optimal performance was achieved on re-Mg6Al1-LDH-Pt with a GLY conversion of 87.6% and a GLYA yield of 58.6%, which exceeded the traditional activated carbon and oxide supports. A combinative study on structural characterizations (XANES, CO-FTIR spectra, and benzoic acid titration) proves that a higher Mg/Al molar ratio promotes the formation of positively charged Ptδ+ species at metal-support interface, which accelerates bond cleavage of α-C–H and improves catalytic activity. Moreover, a higher Mg/Al molar ratio provides a stronger basicity of support that contributes to the oxidation of terminal-hydroxyl and thus enhances the selectivity of GLYA. This catalyst with tunable metal-support interaction shows prospective applications toward transformation of biomass-based polyols.