Search

Upcycling Cr-containing sulfate waste into catalysts for CO2 hydrogenation reaction benefits both pollution mitigation and economic sustainability. In this study, FeCrO3/Fe2O3 catalysts were successfully prepared by a simple hydrothermal method using Cr-containing sodium sulfate (Cr-SS) as a Cr source for efficient conversion and stable treatment of Cr. The removal rate of Cr in Cr-SS can reach 99.9% at the optimized hydrothermal conditions. When the synthesized catalysts were activated and used for the CO2 hydrogenation reaction, a 50% increase in CO2 conversion was achieved compared with the catalyst prepared by impregnation with a comparable amount of Cr. According to the extraction and risk assessment code (RAC) of the Reference Office of the European Community Bureau (BCR), the synthesized FeCrO3/Fe2O3 is risk-free. This work not only realizes the detoxification of the Cr-SS but transfers Cr into stable FeCrO3 for application in a catalytic field, which provides a strategy for the harmless disposal and resource utilization of Cr-containing hazardous waste. [ABSTRACT FROM AUTHOR]

Photocatalytic water splitting for hydrogen production is an effective way to solve energy crisis. However, the challenge of how to solve the problem of short exciton lifetime of the catalyst still remains. In this work, a g-C3N4/UNiMOF/NiS2 (GUN) ternary heterojunction (TH) has been successfully constructed using two-dimensional (2D) UNiMOF as a precursor by the partial hydrothermal sulfidation method. As expected, the optimized GUN-40 heterojunction containing 40 mg of UNiMOF (GUN-40) exhibited higher H2 evolution (572 μmol h–1 g–1) and a longer exciton recombination lifetime (τ = 12.12 ns) than those of pure g-C3N4 (0.67 μmol h–1 g–1, 7.87 ns) under visible light. In addition, the apparent quantum yield (AQY) of GUN-40 was up to 1.54 % at 450 nm. Apparently, the GUN TH structure effectively promotes electron transfer to the NiS2 active site, allowing a long recombination lifetime, and reduces the probability of recombination of electron holes, thus obviously improving photocatalytic efficiency. This work provides insights into the preparation of a cocatalyst using 2D MOF as a template and construction of the TH structure with good charge separation for efficient photocatalysis. [ABSTRACT FROM AUTHOR]

In low permeability reservoirs, water injection is the main means to supplement formation energy, and water quality is a key factor influencing the effect of waterflooding. However, the water quality is defined corresponding to large ranges of permeability under the current standard, which restricts the effective implementation of fine water injection into low permeability reservoirs. In this paper, throat distribution and contribution of mainstream throat to the permeability of low permeability reservoirs were analyzed, and the range of throats that influences water injection effect in such reservoirs was illustrated. Laboratory waterflooding physical simulation experiments on cores were conducted to quantitatively analyze the impacts of clay particle migration and hydration expansion on the seepage ability, and depending on the characteristics of throat distribution, quantify the damages to reservoirs caused by particle size and concentration of suspended solids in injected water. The particle size and concentration limits of suspended solids in injected water were proposed for low permeability reservoirs. [ABSTRACT FROM AUTHOR]

The essential oil of the aerial parts of Amethystea caerulea L. was obtained from steam distillation and investigated by GC and GC-MS. The main components of the essential oil were morrilol (25.1%), 4-vinylguaiacol (14.3%) and acetoanisole (14.3%), followed by linalool (6.6%), eugenol (5.8%) and α-caryophyllene (5.2%). The essential oil showed pronounced contact toxicity against Drosophila melanogaster L. and maize weevil, Sitophilus zeamais (Motsch.), with LD50 values of 5.18 and 50.45 µg per adult, respectively. The essential oil also possessed strong fumigant toxicity against the maize weevils with an LC50 value of 25.39 µg mL−1. [ABSTRACT FROM AUTHOR]

During our screening programme for agrochemicals from Chinese medicinal herbs, the root bark essential oil of Periploca sepium was found to possess strong contact toxicity against the fruit flies, Drosophila melanogaster with a LD50 value of 1.22 µg/adult. The main component of the essential oil was identified to be 2-hydroxy-4-methoxy-benzaldehyde (78.8%), followed by linalool (2.8%) and (−)-α-terpineol (2.7%). The 2-hydroxy-4-methoxy-benzaldehyde was further isolated and identified by bioassay-directed fractionation. The compound showed strong contact toxicity against D. melanogaster and the maize weevil (Sitophilus zeamais) with LD50 values of 1.47 and 6.99 µg/adult, respectively. [ABSTRACT FROM AUTHOR]

γ-Al2O3 nanosheet supported rhodium catalysts with Rh loadings between 0.05 and 2 wt% were prepared by the impregnation method and used for dry reforming of methane (DRM). It was found that Rh species on γ-Al2O3 nanosheets demonstrated excellent stability against sintering at high temperature. After calcining in air at 800 °C followed by reducing with hydrogen at 600 °C, the average particle size of Rh at maximum distribution increases from 1.0 ± 0.3 to 1.8 ± 0.3 nm with an increase in Rh loadings in the catalysts from 0.05 to 2 wt%. Even after reducing with hydrogen at 900 °C, the average size of Rh particles in the catalysts still remained below 2 nm. The results of catalytic performance evaluation show that CH4 and CO2 conversions of 84% and 90%, respectively, with a H2/CO ratio in syngas close to unity can be achieved with a catalyst of Rh loading of only 0.05 wt% at 750 °C. The performance of the catalyst remains stable for more than 200 h. No significant aggregation of the Rh particles is observed on the catalyst after the reaction. The results of XPS, H2-TPR and O2-TPD characterization methods indicate that the strong interaction between Rh and the γ-Al2O3 nanosheets plays a key role in increasing the dispersion of Rh species in the catalyst and preventing it from sintering under high temperature conditions. This factor is also responsible for the superior activity and stability of the catalyst with extremely low Rh loading for the DRM reaction.