Hydrogen sorption properties of ultrasmall Pd nanoparticles (2.5 nm) embedded in a mesoporous carbon template have been determined and compared to those of the bulk system. Downsizing the Pd particle size introduces significant modifications of the hydrogen sorption properties. The total amount of stored hydrogen is decreased compared to bulk Pd. The hydrogenation of Pd nanoparticles induces a phase transformation from fcc to icosahedral structure, as proven by in situ XRD and EXAFS measurements. This phase transition is not encountered in bulk because the 5-fold symmetry is nontranslational. The kinetics of desorption from hydrogenated Pd nanoparticles is faster than that of bulk, as demonstrated by TDS investigations. Moreover, the presence of Pd nanoparticles embedded in CT strongly affects the desorption from physisorbed hydrogen, which occurs at higher temperature in the hybrid material compared to the pristine carbon template.
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http://dx.doi.org/10.1021/ja101795g | DOI Listing |
Sci Total Environ
January 2025
Department of Geosciences & Natural Resource Management, Geology, University of Copenhagen, Denmark.
Due to increasing plastic production, the continuous release of primary and secondary nanoplastic particles (NPs, <1 μm) has become an emerging contaminant in terrestrial environments. The fate and transport of NPs in subsurface environments remain poorly understood, largely due to the complex interplay of mineralogical, chemical, biological, and morphological heterogeneity. This study examines interactions between abundant subsurface minerals and NPs under controlled water chemistry (1 mM KCl, pH 5.
View Article and Find Full Text PDFSmall
January 2025
State Key Laboratory of Fine Chemicals, Frontier Science Center for Smart Materials, School of Chemical Engineering, Dalian University of Technology, Liaoning, Dalian, 116024, China.
Membrane technology has been explored for separating helium from hydrogen in natural gas reservoirs, a process that remains extremely challenging due to the sub-Ångstrom size difference between H and He molecules. Reverse-selective H/He separation membranes offer multiple advantages over conventional helium-selective membranes, which, however, suffer from low H/He selectivity. To address this hurdle, a novel approach is proposed to tune the ultra-micropores of carbon molecular sieves (CMS) membranes through fluorination of the polymer precursor.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
National Institute of Chemistry Slovenia: Kemijski institut, Inorganic Chemistry and Technology, Hajdrihova 19, 1000, Ljubljana, SLOVENIA.
Efficient CO2 capture at concentrations between 400-2000 ppm is essential for maintaining air quality in a habitable environment and advancing carbon capture technologies. This study introduces NICS-24 (National Institute of Chemistry Structures No. 24), a Zn-oxalate 3,5-diamino-1,2,4-triazolate framework with two distinct square-shaped channels, designed to enhance CO2 capture at indoor-relevant concentrations.
View Article and Find Full Text PDFEnviron Geochem Health
January 2025
Institute of Soil and Environmental Sciences, Pir Mehr Ali Shah Arid Agriculture University, Rawalpindi, 46300, Pakistan.
Although the use of biochar as an adsorbent for the removal of various pollutants from wastewater is well established, the use of biochar/modified biochar for the scavenging of antibiotics from aqueous media in the Fenton-like system receives less attention. The highest kasugamycin (KSM) adsorption capacity (5.0 mg g) was obtained from the pristine biochar at the lowest initial pH of 3 in Fenton-like system.
View Article and Find Full Text PDFFood Res Int
January 2025
Department of Food Science, University of Copenhagen, Rolighedsvej 26, 1958 Frederiksberg, Denmark. Electronic address:
The efficiency of ultrafiltration (UF) of acidified skim milk (SM) is impaired by protein aggregation and mineral scaling. The aim of this study is to assess the potential of acidification by electrodialysis with bipolar membranes (EDBM), in comparison with citric acid (CA), prior to the UF process on filtration performance, fouling and composition of the protein concentrates. Electro-acidification, facilitated by a water-splitting reaction, decreased the pH of milk to ∼ 5.
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