Systematic density functional theory calculations and ab initio atomistic thermodynamics were applied to investigate the stability of seven metallic Mo surfaces [(110), (211), (111), (321), (310), (210) (100)] and their coverage dependent hydrogen adsorption. Only dissociative hydrogen adsorption is favored on these surfaces up to more than one monolayer saturation coverage. The computed hydrogen desorption temperatures on Mo(100) at 500 K and on Mo(110) at 410 K are in agreement with the available temperature-programmed desorption results. Under the consideration of H2 as the reduction reagent in Mo catalyst preparation, the computed surface morphology of Mo single crystal shows only exposed (110), (211) and (100) at high temperature; and the estimated surface proportion order of (110) > (211) > (100) agrees very well with the X-ray diffraction detected intensity order of (110) > (211) > (100). Surface reconstruction upon hydrogen adsorption has also been discussed.
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http://dx.doi.org/10.1039/c5cp07349a | DOI Listing |
Chem Sci
January 2025
Centre for Membrane Separations, Adsorption, Catalysis and Spectroscopy for Sustainable Solutions (cMACS), KU Leuven Celestijnenlaan 200F, Post Box 2454 3001 Leuven Belgium
Plastic waste conversion into valuable chemicals is a promising alternative to landfill or incineration. In particular, the chemical upcycling of polybutadiene rubber (PBR) could provide a renewable route towards highly desirable α,ω-dienes with varying chain lengths, which can find ample industrial application. While previous research has shown that the treatment of polybutadiene with a consecutive hydrogenation and ethenolysis reaction can afford long-chain α,ω-dienes, achieving precise control over the product chain length remains an important bottleneck.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
The State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology, Wuhan, 430081, China.
At present, the modification of palladium (Pd) catalysts is an important topic due to its potential to enhance catalytic performance and reduce catalyst costs. In this work, boron (B) and carbon (C) are interstitially doped into the subsurface of Pd to construct PdB and PdC catalysts. The adsorption properties of acetylene and ethylene, the mechanism of acetylene hydrogenation, and ethylene selectivity are studied based on density functional theory (DFT) calculations.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Department of Materials-Oriented Chemical Engineering, College of Chemical Engineering, Fuzhou University, Fuzhou 350116, China.
Electronic grade hydrogen peroxide plays a crucial role in the fabrication of large-scale integrated circuits. However, hydrogen peroxide prepared by the anthraquinone method contains impurities such as lead ions (Pb) and phosphate, which can seriously affect the yield of the circuit. Traditional adsorbent materials have difficulty in solving the problem of simultaneous adsorption of trace anions and cations in hydrogen peroxide due to the single adsorption site and poor adsorption kinetics.
View Article and Find Full Text PDFAdv Mater
January 2025
Department of Chemistry, Tsinghua University, Beijing, 100084, P. R. China.
Electrochemical oxidation of small molecules shows great promise to substitute oxygen evolution reaction (OER) or hydrogen oxidation reaction (HOR) to enhance reaction kinetics and reduce energy consumption, as well as produce high-valued chemicals or serve as fuels. For these oxidation reactions, high-valence metal sites generated at oxidative potentials are typically considered as active sites to trigger the oxidation process of small molecules. Isolated atom site catalysts (IASCs) have been developed as an ideal system to precisely regulate the oxidation state and coordination environment of single-metal centers, and thus optimize their catalytic property.
View Article and Find Full Text PDFAdv Mater
January 2025
State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structures and School of Chemistry and Chemical Engineering, Guangxi University, Nanning, 530004, China.
Efficient and stable electrocatalytic hydrogen evolution reaction (HER) at high current densities is highly desirable for industrial-scale hydrogen production, which is yet challenging, because of the electrocatalyst with short lifespans during the acidic HER process. Here, a controllable preparation technique is successfully developed to synthesize PdPtRuRhAu high-entropy alloys (HEAs) of various sizes, within the 3.14 nm particles (HEA-3.
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