Benzoic acid

About: Benzoic acid is a research topic. Over the lifetime, 11832 publications have been published within this topic receiving 167127 citations. The topic is also known as: Retardex & E210.

Single-step, highly active, and highly selective nanoparticle catalysts for the hydrogenation of key organic compounds

Abstract: Pores for cluster catalysts: Nanoparticles of both Ru5Pt and Ru10Pt2, uniformly distributed along the inner walls of mesoporous silica, exhibit high catalytic performance in the single-step hydrogenation of dimethyl terephthalate (DMT, to 1,4-cyclohexanedimethanol (CHDM); see scheme), of benzoic acid (to cyclohexane carboxylic acid), and of naphthalene (in the presence of sulfur) to cisdecalin.

Influence of relative humidity on the photocatalytic oxidation (PCO) of toluene by TiO2 loaded on activated carbon fibers: PCO rate and intermediates accumulation

Abstract: Photocatalytic oxidation (PCO) tests were carried out for toluene adsorbed on the activated carbon fibers (ACFs)-supported TiO2 photocatalyst in an environmental condition controlled chamber. TiO2/ACF catalyst was made and characterized by N2 adsorption isotherm for pore structure and scanning electron microscopy (SEM) for morphology, respectively. Through exploring the remnant of toluene and the accumulation of intermediates on the TiO2/ACF catalyst including species, amount and their change processes under different relative humidity (RH), this study aimed to explore the influence of RH on the PCO of toluene and the roles of water vapor in the PCO process: PCO reaction paths and the accumulation of intermediates on the TiO2/ACF catalyst. Results showed that (1) with the increase of RH in the chamber (15%, 30%, 45% and 60%) the PCO conversion rate of toluene was positive correlated and no catalyst deactivation was observed under all RH levels; (2) during the gas–solid PCO process of toluene, byproducts of aromatic ring oxidation including 2-methyl, p-benzoquinone and o(m, p)-cresol were observed on the TiO2/ACF catalyst which had not been reported, together with the intermediates of side chain oxidation including benzyl alcohol, benzaldehyde and benzoic acid which had been reported; (3) although benzaldehyde was the primary intermediate under all RH level, amounts of the byproducts of aromatic ring oxidation were increased with the increase of RH; and (4) elevated RH increased the accumulation of benzyl alcohol but assuredly decreased the accumulation of benzaldehyde. These results suggested that (1) RH affects both the PCO rate and the PCO reaction path of toluene; (2) although methyl group oxidation is the major path, aromatic ring oxidation, which is not the expected path for the PCO of toluene, is enhanced when the RH increases; (3) apart from the role of hydroxyl radical (OH) produced from water by TiO2, water molecule also directly takes part in the PCO process. A hypothesis has been suggested: transition species comprised of benzaldehyde, hydroxyl and water molecule exists in the PCO conversion process from benzaldehyde to benzoic acid, though the hypothesis has not been confirmed.

Probing ring-opening pathways for efficient photocatalytic toluene decomposition

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.

Metabolite Profiles of Lactic Acid Bacteria in Grass Silage

Abstract: The metabolite production of lactic acid bacteria (LAB) on silage was investigated. The aim was to compare the production of antifungal metabolites in silage with the production in liquid cultures previously studied in our laboratory. The following metabolites were found to be present at elevated concentrations in silos inoculated with LAB strains: 3-hydroxydecanoic acid, 2-hydroxy-4-methylpentanoic acid, benzoic acid, catechol, hydrocinnamic acid, salicylic acid, 3-phenyllactic acid, 4-hydroxybenzoic acid, (trans, trans)-3,4-dihydroxycyclohexane-1-carboxylic acid, p-hydrocoumaric acid, vanillic acid, azelaic acid, hydroferulic acid, p-coumaric acid, hydrocaffeic acid, ferulic acid, and caffeic acid. Among these metabolites, the antifungal compounds 3-phenyllactic acid and 3-hydroxydecanoic acid were previously isolated in our laboratory from liquid cultures of the same LAB strains by bioassay-guided fractionation. It was concluded that other metabolites, e.g., p-hydrocoumaric acid, hydroferulic acid, and p-coumaric acid, were released from the grass by the added LAB strains. The antifungal activities of the identified metabolites in 100 mM lactic acid were investigated. The MICs against Pichia anomala, Penicillium roqueforti, and Aspergillus fumigatus were determined, and 3-hydroxydecanoic acid showed the lowest MIC (0.1 mg ml−1 for two of the three test organisms).