Carbon nitride used as a reactive template to prepare mesoporous molybdenum sulfide and nitride
TL;DR: In this paper, carbon nitride C3N4 has been used as a sacrificial template to prepare inorganic materials with hierarchical pore structure, which has been demonstrated in the thiophene hydrodesulfurization and electrochemical hydrogen evolution reaction (HER).
Abstract: Carbon nitride C3N4 has been used as a sacrificial template to prepare inorganic materials with hierarchical pore structure. C3N4 impregnated with ammonium heptamolybdate was treated in reactive gas mixtures (H2S/H2 or NH3/H2). This approach allowed mesoporous molybdenum sulfide and molybdenum nitride materials to be obtained that replicate the morphology of the C3N4 template. Advantageous catalytic properties have been demonstrated in the thiophene hydrodesulfurization (HDS) and electrochemical hydrogen evolution reaction (HER). The highest rates in both reactions were observed for partially sulfidized Mo2N solid.
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TL;DR: In this paper , a review of the research progress of unsupported HDS catalysts for the HDS of fuel is provided, followed by the developments of template-free methods and template methods for preparing unsupported catalysts.
9 citations
TL;DR: In this article , a series of three-dimensional porous (3DP) CoxMo/MF supported HDS catalysts were constructed and the properties of the obtained catalysts are characterized by XRD, TG, SEM, TEM, and low-temperature N2 adsorption-desorption techniques.
3 citations
TL;DR: In this article , a one-pot synthesis from ammonium thiomolybdate (NH4)2MoS2 and urea-thiourea mixture is presented, which is characterized by several physical techniques and tested in the thiophene hydrodesulfurization model reaction and in photocatalytic hydrogen evolution reaction (PHER).
1 citations
TL;DR: In this article , the role of the substrate in the photochemical reactivity of an identical probe molecule, ethyl chloride (EC), when excited by pulsed 532 nm laser under ultrahigh vacuum (UHV) conditions was investigated.
Abstract: Photochemical and photocatalytic activity of adsorbates on surfaces is strongly dependent on the nature of a given substrate and its resonant absorption of the (visible) light excitation. An observation is reported here of the visible light photochemical response of formamidinium lead bromide (FAPbBr3) halide perovskite and carbon nitride (CN) thin-film materials (deposited on a SiO2/Si(100) substrate), both of which are known for their photovoltaic and photocatalytic properties. The goal of this study was to investigate the role of the substrate in the photochemical reactivity of an identical probe molecule, ethyl chloride (EC), when excited by pulsed 532 nm laser under ultrahigh vacuum (UHV) conditions. Postirradiation temperature-programmed desorption (TPD) measurements have indicated that the C–Cl bond dissociates following the visible light excitation to form surface-bound fragments that react upon surface heating to form primarily ethane and butane. Temperature-dependent photoluminescence (PL) spectra of the FAPbBr3 films were recorded and decay lifetimes were measured, revealing a correlation between length of PL decay and the photoreactivity yield. We conclude that the FAPbBr3 material with its absorption spectrum in resonance with visible light excitation (532 nm) and longer PL lifetime leads to three times faster (larger cross-section) photoproduct formation compared with that on the CN substrate. These results contrast the behavior under ambient conditions where the CN materials are photochemically superior due, primarily, to their stability within humid environments.
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TL;DR: An overview of recent developments in the non-noble metal catalysts for electrochemical hydrogen evolution reaction (HER) is presented, with emphasis on the nanostructuring of industrially relevant hydrotreating catalysts as potential HER electrocatalysts.
Abstract: Progress in catalysis is driven by society's needs. The development of new electrocatalysts to make renewable and clean fuels from abundant and easily accessible resources is among the most challenging and demanding tasks for today's scientists and engineers. The electrochemical splitting of water into hydrogen and oxygen has been known for over 200 years, but in the last decade and motivated by the perspective of solar hydrogen production, new catalysts made of earth-abundant materials have emerged. Here we present an overview of recent developments in the non-noble metal catalysts for electrochemical hydrogen evolution reaction (HER). Emphasis is given to the nanostructuring of industrially relevant hydrotreating catalysts as potential HER electrocatalysts. The new syntheses and nanostructuring approaches might pave the way for future development of highly efficient catalysts for energy conversion.
1,882 citations
TL;DR: In this article, the authors proposed a cost-effective molybdenum phosphide that exhibits high activity towards the hydrogen evolution reaction (HER) in both acid and alkaline media even in bulk form.
Abstract: Electrochemical production of hydrogen from water has been directed to the search for non-noble metal based and earth-abundant catalysts. In this work, we propose a novel cost-effective catalyst, molybdenum phosphide that exhibits high activity towards the hydrogen evolution reaction (HER) in both acid and alkaline media even in bulk form. Comparative analysis of Mo, Mo3P and MoP as catalysts for HER clearly indicates that phosphorization can potentially modify the properties of the metal and different degrees of phosphorization lead to distinct activities and stabilities. Theoretical calculations by density functional theory also show that a simple phosphorization of molybdenum to form MoP introduces a good ‘H delivery’ system which attains nearly zero binding to H at a certain H coverage. With the combination of experimental results and theoretical calculations, this work has enlightened a new way of exploring cost-effective catalysts for HER.
1,091 citations
TL;DR: Molybdenum disulphide is identified as a promising cost-effective substitute for noble metal catalysts and shows superior carbon dioxide reduction performance compared with the noble metals with a high current density and low overpotential in an ionic liquid.
Abstract: Electrochemical reduction is one process to produce higher value chemicals from carbon dioxide, and it is typically catalysed by noble metals. Here, the authors demonstrate that molybdenum disulphide is also capable of efficiently catalysing the reaction in the presence of an ionic liquid.
616 citations
TL;DR: In this article, temperature-programmed reaction between MoO3 or WO3 with NH3 provides a new way to prepare Mo2N and W2N powders with specific surface areas as high as 220 and 91 m2 g−1, respectively, corresponding to 3- to 4-nm crystallites.
506 citations
TL;DR: In this article, transmission electron microscopy (TEM), dynamic oxygen chemisorption (DOC), and EXAFS were used to characterize supported MoS2 catalysts.
354 citations