The adsorption of CO on polycrystalline TiO2 was investigated by static adsorption microcalorimetry. The initial differential heat of adsorption (qdiff,0) of CO on polycrystalline titania is 40 kJ/mol, and the standard adsorption entropy (Deltas0) is -104 J mol(-1) K(-1). These results are consistent with those derived from temperature-programmed desorption and FTIR results in the literature. The good reproducibility of the isotherms and the stable qdiff indicate that the lattice oxygen and hydroxyl groups on titania surface are basically not reactive to adsorbed CO.
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http://dx.doi.org/10.1021/la7014594 | DOI Listing |
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January 2025
Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, Delhi, 110016, India.
Crystalline γ-FeO(OH) dominantly possessing ─OH terminals (𝛾-FeO(OH)), polycrystalline γ-FeO(OH) containing multiple ─O, ─OH, and Fe terminals (𝛾-FeO(OH)), and α-FeO majorly containing ─O surface terminals are used as electrocatalysts to study the effect of surface terminals on electrocatalytic nitrate reduction reaction (eNORR) selectivity and stabilization of reaction intermediates. Brunauer-Emmett-Teller analysis and electrochemically determined surface area suggest a high active surface area of 117.79 m g (ECSA: 0.
View Article and Find Full Text PDFAdv Mater
December 2024
Hefei National Research Center for Physical Sciences at the Microscale, School of Chemistry and Materials Science, Key Laboratory of Energy Conversion Materials, Chinese Academy of Sciences, University of Science and Technology of China, Hefei, Anhui, 230026, P. R. China.
Crystallization process is critical for enhancing the crystallinity, regulating the crystal orientation of polycrystalline thin films, as well as repairing defects within the films. For quasi-1D SbSe photovoltaic materials, the preparation of SbSe thin films still faces great challenges in adjusting orientation and defect properties, which limits the device performance. In this study, a novel post-treatment strategy is developed that uses a low melting point BO coating layer as a flux to drive the recrystallization of SbSe, thereby regulating the micro-orientation of thermal evaporation-derived SbSe films and optimizing their electrical properties.
View Article and Find Full Text PDFJ Phys Chem C Nanomater Interfaces
November 2024
Departament de Ciència de Materials i Química Física and Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, c/Martí i Franquès 1-11, Barcelona 08028, Spain.
Hydrogen adatoms are involved in many reactions catalyzed by Transition Metal (TM) surfaces, such as the Haber-Bosch process or the reverse water gas shift reaction, key to our modern society. Any rational improvement on such a catalyst requires an atomistic knowledge of the metal↔hydrogen interaction, only attainable from first-principles calculations on suited, realistic models. The present thorough density functional theory study evaluates such H interaction at a low coverage on most stable surfaces of , , and TMs.
View Article and Find Full Text PDFACS Catal
November 2024
Institute of Materials Chemistry, TU Wien, Getreidemarkt 9/BC, 1060 Vienna, Austria.
A combined surface science/microreactor approach was applied to examine interface effects in ethylene hydrogenation on carbon-supported Ag, Au, and Cu nanoparticle catalysts. Turnover frequencies (TOFs) were substantially higher for supported catalysts than for (unsupported) polycrystalline metal foils, especially for Ag. Spark ablation of the corresponding metals on highly oriented pyrolytic graphite (HOPG) and carbon-coated grids yielded nanoparticles of around 3 nm size that were well-suited for characterization by X-ray photoelectron spectroscopy (XPS), high-resolution (scanning) transmission electron microscopy (HRTEM/STEM), and energy dispersive X-ray spectroscopy (EDX).
View Article and Find Full Text PDFPhys Chem Chem Phys
November 2024
IITEMA, CONICET, Universidad Nacional de Río Cuarto, Ruta Nac. 36, Km 601, Río Cuarto, Córdoba 5800, Argentina.
The modification of metallic surfaces with adsorbed atoms of a second metal is presented as an ideal method for producing electrocatalysts. In this work, we examined the role of Au atoms in the reactivity of Pt surfaces and their effect on the adsorption and diffusion of CO using first-principles calculations. Our comprehensive study utilized density functional theory (DFT) to analyze a variety of adsorption sites on single-crystal Pt structures, encompassing open and staggered configurations.
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