In this work, we demonstrate that amorphous and porous molybdenum silicate microspheres are highly active catalysts for heterogeneous propylene metathesis. Homogeneous molybdenum silicate microspheres and aluminum-doped molybdenum silicate microspheres were synthesized via a nonaqueous condensation of a hybrid molybdenum biphenyldicarboxylate-based precursor solution with (3-aminopropyl)triethoxysilane. The as-prepared hybrid metallosilicate products were calcined at 500 °C to obtain amorphous and porous molybdenum silicate and aluminum-doped molybdenum silicate microspheres with highly dispersed molybdate species inserted into the silicate matrix. These catalysts contain mainly highly dispersed MoO species, which possess high catalytic activity in heterogeneous propylene metathesis to ethylene and butene. Compared to conventional silica-supported MoO catalysts prepared via incipient wetness impregnation (MoIWI), the microspheres with low Mo content (1.5-3.6 wt %) exhibited nearly 2 orders of magnitude higher steady-state propylene metathesis rates at 200 °C, approaching site time yields of 0.11 s.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC10563125 | PMC |
http://dx.doi.org/10.1021/acscatal.3c02045 | DOI Listing |
Astrobiology
December 2024
Department of Mineralogy, University of Hannover, Germany.
Nontraditional stable isotopes of bioactive metals emerged as novel proxies for reconstructing the biogeochemical cycling of metals, which serve as cofactors in major metabolic pathways. The fractionation of metal isotopes between ambient fluid and microorganisms is ultimately recorded in authigenic minerals, such as carbonates, which makes them potentially more reliable than standard biomarkers in organic matter. Stromatolitic carbonates are geochemical archives that allow for the study of the long-term interplay of the biosphere, atmosphere, and hydrosphere through deep time, with the unique potential to investigate early life environments and the evolution of the metallome.
View Article and Find Full Text PDFEnviron Res
December 2024
Hubei Key Laboratory of Mineral Resources Processing and Environment, School of Resources and Environmental Engineering, State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan, 430070, China; The James Hutton Institute, Craigiebuckler, Aberdeen, AB15 8QH, UK. Electronic address:
An efficient catalyst of molybdenum disulfide (MoS) coupled with ball milling modified sludge biochar (BMSBC) was prepared to efficiently activate peroxymonosulfate (PMS) for neonicotinoids elimination. As expected, 95.1% of imidacloprid (IMI) was degraded by PMS/BMSBC system within 60 min and it was accompanied by the outstanding mineralization rate of 71.
View Article and Find Full Text PDFRapid Commun Mass Spectrom
November 2024
St. Petersburg State Institute of Technology, St. Petersburg, Russian Federation.
Rationale: Ceria-based systems are of great interest because of their unique properties. Such systems may be used as anode materials for SOFCs or in oxygen sensors. The exploitation of these materials often requires high temperatures.
View Article and Find Full Text PDFJ Colloid Interface Sci
December 2024
State Key Laboratory of Silicate Materials for Architectures and School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan 430070, PR China; Laboratory of Solar Fuel, Faculty of Materials Science and Chemistry, China University of Geosciences, 68 Jincheng Street, Wuhan, 430078, PR China. Electronic address:
The rationally designing and constructing atomic-level heterointerface of two-dimensional (2D) chalcogenides is highly desirable to overcome the sluggish HO-activation process toward efficient solar-driven hydrogen evolution. Herein, a novel in-plane 2D/2D molybdenum disulfide-rhenium disulfide (ReS-MoS) heterostructure is well-designed to induce the charge self-regulation of active site by forming electron-enriched Re and electron-deficient S sites, thus collectively facilitating the activation of adsorbed HO molecules and its subsequent H evolution. Furthermore, the obtained in-plane heterogenous ReS-MoS nanosheet can powerfully transfer photoexcited electrons to inhibit photocarrier recombination as observed by advanced Kelvin probe measurement (KPFM), in-situ X-ray photoelectron spectroscopy (XPS) and femtosecond transient absorption spectroscopy (fs-TAS).
View Article and Find Full Text PDFTalanta
August 2024
Department of Oceanography, University of Hawaii, 1000 Pope Road, Honolulu, HI, 96822, USA. Electronic address:
The silicate (Si) molybdenum blue method was modified by combining oxalate and ascorbic acid into a single reagent and was used for determining Si in sea water samples. The first step of this automated assay protocol was designed to perform either a calibration by a single Si standard prepared in deionized (DI) water, or to dilute samples in the range of 0-160 μM Si to fit into 0-20 μM Si calibration range using a 20 cm flow cell. By designing the assay protocol to function in batch mode, the influence of salinity on calibration was eliminated, thus making the method suitable for analysis of samples collected in the open ocean, coastal areas, or rivers.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!