Angew Chem Int Ed Engl
September 2024
Liquid organic hydrogen carriers (LOHCs) are attractive platform molecules that play an important role in hydrogen energy storage and utilization. The multi-step hydrogenation of toluene (TOL) to methylcyclohexane (MCH) has been widely studied in the LOCHs systems, due to their relatively low toxicity and reasonable hydrogen storage capacity. Noble metal catalysts such as Ru has exhibited good performance in multi-step hydrogenation reactions, while the application is still hindered by their high cost and low specific activity.
View Article and Find Full Text PDFElectrocatalytic oxidation of C-H bonds in hydrocarbons represents an efficient and sustainable strategy for the synthesis of value-added chemicals. Herein, a highly selective and continuous-flow electrochemical oxidation process of toluene to various oxygenated products (benzyl alcohol, benzaldehyde, and benzyl acetate) is developed with the electrocatalytic membrane electrodes (ECMEs). The selectivity of target products can be manipulated via surface and interface engineering of CoO-based electrocatalysts.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
Precise regulation of the active site structure is an important means to enhance the activity and selectivity of catalysts in CO electroreduction. Here, we creatively introduce anionic groups, which can not only stabilize metal sites with strong coordination ability but also have rich interactions with protons at active sites to modify the electronic structure and proton transfer process of catalysts. This strategy helps to convert CO into fuel chemicals at low overpotentials.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
October 2023
Carbonate hydrogenation to formate is a promising route to convert captured carbon dioxide into valuable chemicals, thus reducing carbon emissions and creating a revenue return. Developing inexpensive catalysts with high activity, selectivity, and stability remains challenging. We report a supported non-noble metal catalyst, Ni/TiO , with great selectivity over 96 % and excellent stability in catalyzing the conversion of carbonate into formate in aqueous solution.
View Article and Find Full Text PDFSingle-site pincer-ligated iridium complexes exhibit the ability for C-H activation in homogeneous catalysis. However, instability and difficulty in catalyst recycling are inherent disadvantages of the homogeneous catalyst, limiting its development. Here, we report an atomically dispersed Ir catalyst as the bridge between homogeneous and heterogeneous catalysis, which displays an outstanding catalytic performance for n-butane dehydrogenation, with a remarkable n-butane reaction rate (8.
View Article and Find Full Text PDFA simple and efficient strategy was developed for the synthesis of Pd single-atom catalysts (Pd/G) by nitric acid vapor-assisted redispersion. The as-prepared Pd/G displayed robust catalytic performance in the selective hydrogenation reaction of benzaldehyde. This work paves a new way for the design of supported Pd single-atom catalysts.
View Article and Find Full Text PDFTransition metal sulfides (TMSs) are promising electrocatalysts for hydrogen evolution reaction (HER), while TMSs usually suffer from inevitable surface oxidation in air, and the impact of the surface oxidation on their HER catalytic activity remains unclear. Herein, we demonstrate an effective strategy for reducing the surface oxidation degree of easily oxidized CoS by introducing glued vanadium pentoxide (VO) nanoclusters, taking advantage of the preferential adsorption and strong interaction between high-valence V and O. Combining oxidation protection and elaborate oxidation control experiments reveal that reduced surface oxidation degree of CoS is conducive to affording promising HER catalytic performance, as the oxidized surface of CoS can hinder the dissociation of water and thus is harmful to the HER process.
View Article and Find Full Text PDFHydrogen is increasingly being discussed as clean energy for the goal of net-zero carbon emissions, applied in the proton-exchange-membrane fuel cells (PEMFC). The preferential oxidation of CO (PROX) in hydrogen is a promising solution for hydrogen purification to avoid catalysts from being poisoned by the trace amount of CO in hydrogen-rich fuel gas. Here, we report the fabrication of a novel bimetallic Pt-Fe catalyst with ultralow metal loading, in which fully-exposed Pt clusters bonded with neighbor atomically dispersed Fe atoms on the defective graphene surface.
View Article and Find Full Text PDFConsiderable attention has been drawn to tune the geometric and electronic structure of interfacial catalysts via modulating strong metal-support interactions (SMSI). Herein, we report the construction of a series of TiO/Ni catalysts, where disordered TiO overlayers immobilized onto the surface of Ni nanoparticles (~20 nm) are successfully engineered with SMSI effect. The optimal TiO/Ni catalyst shows a CO conversion of ~19.
View Article and Find Full Text PDFIn heterogeneous catalysis, the interface between active metal and support plays a key role in catalyzing various reactions. Specially, the synergistic effect between active metals and oxygen vacancies on support can greatly promote catalytic efficiency. However, the construction of high-density metal-vacancy synergistic sites on catalyst surface is very challenging.
View Article and Find Full Text PDFHaving the excellent catalytic performance, single atom catalysts (SACs) arouse extensive research interest. However, the application of SACs is hindered by the lack of versatile and scalable preparation approaches. Here, we show a precursor-atomization strategy to produce SACs, involving the spray of droplets of solutions containing metal precursors onto support surface through ultrasonic atomization and the subsequent calcination.
View Article and Find Full Text PDFThe atomically dispersed metal catalyst or single-atom catalyst (SAC) with the utmost metal utilization efficiency shows excellent selectivity toward ethylene compared to the metal nanoparticles catalyst in the acetylene semi-hydrogenation reaction. However, these catalysts normally work at relatively high temperatures. Achieving low-temperature reactivity while preserving high selectivity remains a challenge.
View Article and Find Full Text PDFHydrogen storage by means of catalytic hydrogenation of suitable organic substrates helps to elevate the volumetric density of hydrogen energy. In this regard, utilizing cheaper industrial crude hydrogen to fulfill the goal of hydrogen storage would show economic attraction. However, because CO impurities in crude hydrogen can easily deactivate metal active sites even in trace amounts such a process has not yet been realized.
View Article and Find Full Text PDFExploring antibacterial nanomaterials with excellent catalytic antibacterial properties has always been a hot research topic. However, the construction of nanomaterials with robust antibacterial activity at the atomic level remains a great challenge. Here a fully-exposed Pd cluster atomically-dispersed on nanodiamond-graphene (Pd /ND@G) with excellent catalytic antibacterial properties is reported.
View Article and Find Full Text PDFSelective hydrogenation of alkynes to alkenes plays a crucial role in the synthesis of fine chemicals. However, how to achieve high selectivity and effective separation of the catalyst and substrate while obtaining high activity is the key for this reaction. In this work, a Pd single-atom catalyst is anchored to the shell of magnetic core-shell particles that consist of a Ni-nanoparticles core and a graphene sheets shell (Ni@G) for semi-hydrogenation of phenylacetylene, delivering 93% selectivity to styrene at full conversion with a robust turnover frequency of 7074 h under mild reaction conditions (303 K, 2 bar H ).
View Article and Find Full Text PDFDry reforming of methane (DRM) has provided an effective avenue to convert two greenhouse gases, CH and CO , into syngas. Here, we design a DRM photocatalyst Rh/Ce WO that invokes both photothermal and photoelectric processes, which overcomes the thermodynamic limitation of DRM under conventional conditions. In contrast to plasmonic or UV-response photocatalysts, our photocatalyst produces a superior light-to-chemical energy efficiency (LTCEE) of 4.
View Article and Find Full Text PDFDirect conversion of methane into value-added chemicals, such as methanol under mild conditions, is a promising route for industrial applications. In this work, atomically dispersed Rh on TiO suspended in an aqueous solution was used for the oxidation of methane to methanol. Promoted by copper cations (as co-catalyst) in solution, the catalysts exhibited high activity and selectivity for the production of methanol using molecular oxygen with the presence of carbon monoxide at 150 °C with a reaction pressure of 31 bar.
View Article and Find Full Text PDFUnderstanding the unique behaviors of atomically dispersed catalysts and the origin thereof is a challenging topic. Herein, we demonstrate a facile strategy to encapsulate Pt species within Y zeolite and reveal the nature of selective hydrogenation over a Pt@Y model catalyst. The unique configuration of Pt@Y, namely atomically dispersed Pt stabilized by the surrounding oxygen atoms of six-membered rings shared by sodalite cages and supercages, enables the exclusive heterolytic activation of dihydrogen over Pt···O units, resembling the well-known classical Lewis pairs.
View Article and Find Full Text PDFWe report the syntheses of highly dispersed CoNi bimetallic catalysts on the surface of α-MoC based on the strong metal support interaction (SMSI) effect. The interaction between the nearly atomically dispersed Co and Ni atoms was observed for the first time by the real-space chemical mapping at the atomic level. Combined with the ability of α-MoC to split water at low temperatures, the as-synthesized CoNi/α-MoC catalysts exhibited robust and synergistic performance for the hydrogen production from hydrolysis of ammonia borane.
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