Proton exchange membrane fuel cells have strict requirements for the CO concentration in H-rich fuel gas. Here, from the perspective of industrial practicability, a highly dispersed Pt catalyst (2-4 nm) supported on activated carbon (AC), which was modified by electronic promoters (K) and structural promoters (isopropanol), is studied in detail. Compared with traditional metal oxide supports, the K-Pt/AC catalysts, which benefit from the tuned charge distribution, achieve a significant reduction of CO (from 1% to <0.
View Article and Find Full Text PDFLimited cells and factors, inadequate mechanical properties, and necrosis of defects center have hindered the wide clinical application of bone-tissue engineering scaffolds. Herein, we construct a self-oxygenated 3D printed bioactive hydrogel scaffold by integrating oxygen-generating nanoparticles and hybrid double network hydrogel structure. The hydrogel scaffold possesses the characteristics of extracellular matrix; Meanwhile, the fabricated hybrid double network structure by polyacrylamide and CaCl-crosslinked sodium carboxymethylcellulose endows the hydrogel favorable compressive strength and 3D printability.
View Article and Find Full Text PDFCu-based catalysts are a promising alternative to toxic mercury catalysts for acetylene hydrochlorination, but their effectiveness is limited due to the poor dispersion and deactivation caused by reduction, agglomeration, and carbon deposition. In this study, the activity and stability of carbon-supported CuCl catalysts were largely improved by introducing N-heterocyclic ketones. Remarkably, -methyl-2-pyridone (NM2P) coordinated Cu-based catalysts exhibited over 95% acetylene conversion with better stability under the reaction conditions of = 180 °C, GHSV (CH) of 80 h, and / = 1.
View Article and Find Full Text PDFA great challenge for electrochemical CO reduction is to improve energy efficiency, which requires reducing overpotential while increasing product Faraday efficiency. Here, we designedly synthesize a hybrid electrocatalyst consisting of Fe nanoparticles, pyrrole-type Fe-N sites and less-oxygenated carbon supports, which exhibits a remarkable CO Faraday efficiency above 99% at an ultralow overpotential of 21 mV, reaching the highest cathode energy efficiency of 97.1% to date.
View Article and Find Full Text PDFThe utilization of Cu-based catalysts in CO conversion into valuable chemicals is of significant interest due to their potential in mitigating greenhouse gas emissions. However, the controllable design of Cu-based catalysts and the regulation of their mechanism remain challenging. In this study, a series of efficient Cu/L catalysts were prepared for this process, and the intrinsic influencing factors on the reaction routes were systematically revealed.
View Article and Find Full Text PDFA complementary copper-catalyzed and electrochemical aminosulfonylation of -homoallyl benzimidates and -alkenyl amidines with sodium sulfinates was developed. The terminal alkene substrate produced sulfone-containing 1,3-oxazines and tetrahydropyrimidines in the presence of Cu(OAc), AgCO, and DPP, and under similar reaction conditions, sulfonylated tetrahydro-1,3-oxazepines were prepared from 1-aryl-substituted -homoallyl benzimidates in moderate to good yields. For certain electron-rich 1,1-diaryl-substituted alkene substrates, the corresponding tetrahydro-1,3-oxazepines could also be obtained in similar or even higher yields via a green electrochemical technique.
View Article and Find Full Text PDFA green catalyst for acetylene hydrochlorination yielding a VCM is presented using imidazole as a single component metal-free catalyst. The mechanisms and reactivities of imidazole-catalyzed acetylene hydrochlorination have been investigated by combined computational and experimental studies. The electronic effects of ortho-substituents on the reactivities have also been investigated.
View Article and Find Full Text PDFACS Appl Mater Interfaces
July 2019
CuZn alloy, regarded as the active sites, shows excellent catalytic activity for the reverse water gas shift reaction, whereas the incorporation of N atoms, especially pyridinic N, can greatly improve its catalytic properties because of the strong promotion capacity for adsorption and activation of CO molecules. Herein, the synthesis strategy involving Cu-doped Zn-based metal-organic frameworks is utilized to prepare CuZn alloy coated in an N-doped carbon shell. The excellent catalytic ability for CO transformation originates from the synergistic catalytic effect between CuZn alloy and pyridinic N.
View Article and Find Full Text PDFThe objective of this study was to develop an ultrasonic-assisted procedure for the extraction of total phenolics from L blossoms (CAB) and evaluate the free radical scavenging activity and anti-HMG-CoA reductase activity of the total phenolics. In this work, a Box- Behnken design based on single-factor experiments was used to explore the optimum extraction process. Under the optimum conditions (extraction solvent 70.
View Article and Find Full Text PDFAcetylene hydrochlorination is a major industrial technology for manufacturing vinyl chloride monomer in regions with abundant coal resources; however, it is plagued by the use of mercury(II) chloride catalyst. The development of a nonmercury catalyst has been extensively explored. Herein, we report a N-doped carbon catalyst derived from ZIF-8 with both high activity and quite good stability.
View Article and Find Full Text PDFACS Appl Mater Interfaces
March 2016
Mn2O3-doped Fe2O3 hexagonal microsheets were prepared for the low-temperature selective catalytic reduction (SCR) of NO with NH3. These hexagonal microsheets were characterized by SEM, TEM, XRD, BET, XPS, NH3-TPD, H2-TPR, and in situ DRIFT and were shown to exhibit a considerable uniform hexagonal microsheet structure and excellent low temperature SCR efficiency. When doped with different Mn molar ratios, Mn2O3 was detected in the Fe2O3 hexagonal microsheets based on the XRD results without the presence of other MnOX species.
View Article and Find Full Text PDFBio-aviation fuel was firstly synthesized by hydroprocessing castor oil in a continuous-flow fixed-bed microreactor with the main objective to obtain the high yield of aviation fuel and determine the elemental compositions of the product phases as well as the reaction mechanism. Highest aviation range alkane yields (91.6 wt%) were achieved with high isomer/n-alkane ratio (i/n) 4.
View Article and Find Full Text PDFHere, we sequenced the complete mitochondrial genome of Spilornis cheela (Falconiformes, Accipitridae), which is considered as endemic raptor species and listed in the second category of National Key Protected Wild Animals in China. The genome is 18,291 bp in size. Its gene arrangement pattern was identical with that of Spizaetus alboniger.
View Article and Find Full Text PDFMitochondrial DNA
April 2013
The complete mitochondrial genome sequence of Gekko swinhonis was determined in this paper. The genome was 16,818 bp in length and contained 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes, and 1 control region (CR). The gene composition and order of G.
View Article and Find Full Text PDFThe 16,585 base pairs mitochondrial genome of Shinisaurus crocodilurus was determined by using PCR amplification and DNA sequencing. To determine the phylogenetic position of S. crocodilurus with related species within Squamata, the phylogenetic tree was reconstructed with the concatenated nucleotide sequences of the 12 heavy-strand-encoded protein genes.
View Article and Find Full Text PDFIn this paper, we sequenced the complete mitochondrial genome of Kallima inachus (Lepidoptera: Nymphalidae: Nymphalinae), which is considered a rare species in China. The genome is 15,183 bp in size. Its gene arrangement pattern was identical with those of Argynnis hyperbius.
View Article and Find Full Text PDFBlack-spotted and red-spotted tokay geckos are distributed in different regions and have significant differences in morphological appearance, but have been regarded as the same species, Gekko gecko, in taxonomy. To determine whether black-spotted and red-spotted tokay geckos are genetically differentiated, we sequenced the entire mitochondrial cytochrome b gene (1147 bp) from 110 individuals of Gekko gecko collected in 11 areas including Guangxi China, Yunnan China, Vietnam, and Laos. In addition, we performed karyotypic analyses of black-spotted tokay geckos from Guangxi China and red-spotted tokay geckos from Laos.
View Article and Find Full Text PDFIn this paper, we sequenced the complete mitochondrial genome of the Manis pentadactyla (Pholidota: Manidae), which is considered as an endemic species in China. It is listed as a vulnerable species by the International Union for Conservation of Nature and Natural Resources Red List and also an endangered species in China. The genome is 16,578 bp in size.
View Article and Find Full Text PDFJ Environ Manage
November 2011
The effect of the surfactant template cetyltrimethylammonium bromide (CTAB) in MCM-41 on the adsorption of aniline was investigated. Various MCM-41 samples were prepared by controlling template removal using an extraction method. The samples were then used as adsorbents for the removal of aniline from aqueous solution.
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