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1.
Small ; : e2311441, 2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38446057

RESUMO

Tailoring advanced anisotropy-driven efficient separation and migration of photogenerated carriers is a pivotal stride toward enhancing photocatalytic activity. Here, CdS-MoS2 binary photocatalysts are tailored into a dumbbell shape by leveraging the rod-shaped morphology of CdS and employing an in situ tip-induction strategy. To further enhance the photocatalytic activity, an in situ photo-deposition strategy is incorporated to cultivate MnOx particles on the dumbbell-shaped CdS-MoS2 . The in situ deposition of MnOx effectively isolated the oxidatively active sites on the CdS surface, emphasizing the reductively active crystalline face of CdS, specifically the (002) face. Benefiting from its robust activity as a reduction active site, MoS2 adeptly captures photogenerated electrons, facilitating the reduction of H+ to produce hydrogen. The anisotropically driven separation of CdS photogenerated carriers markedly mitigates the Coulomb force or binding force of the photogenerated electrons, thus promoting a smoother migration toward the active site for photocatalytic hydrogen evolution. The hydrogen evolution rate of 35MnOx -CdS-MoS2 -3 surpasses that of CdS by nearly an order of magnitude, achieving a quantum efficiency of 22.30% at 450 nm. Under simulated solar irradiation, it attains a rate of 42.86 mmol g-1 h-1 . This work imparts valuable insights for the design of dual co-catalysts, anisotropy-driven spatial vectorial charge separation and migration, and the analysis of migration pathways of photogenerated carriers.

2.
ChemSusChem ; : e202400484, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38472129

RESUMO

Hydrogenation of CO2 to olefin catalyzed by iron-based catalysts is a sustainable and important way to achieve carbon neutrality. In this study, iron-based catalysts were facilely prepared by direct pyrolysis of ferric fumarate (FF), which are applied to CO2 hydrogenation to olefin reaction to explore the effects of pyrolysis temperature and atmosphere on catalytic performance of the catalysts. Among them, NaFe-Air-400 catalyst exhibits the highest catalytic activity with 33.7 %, and light olefin selectivity reaches as high as 47.1 %. The catalytic performance of pyrolytic catalysts is better than that the impregnated NaFe catalyst on activated carbon (NaFe/AC). A series of XRD, Raman and SEM characterization results show a suitable pyrolysis temperature would promote the balance between amorphous carbon and graphene, which can affect the formation of FexCy phase, leading the distinctive activity and olefin selectivity. Hence, the presented one-step pyrolysis methodology would provide a facile and quick synthesis of highly-active iron-based catalyst design for CO2 conversion.

3.
Nat Commun ; 15(1): 512, 2024 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-38218949

RESUMO

Tuning CO2 hydrogenation product distribution to obtain high-selectivity target products is of great significance. However, due to the imprecise regulation of chain propagation and hydrogenation reactions, the oriented synthesis of a single product is challenging. Herein, we report an approach to controlling multiple sites with graphene fence engineering that enables direct conversion of CO2/H2 mixtures into different types of hydrocarbons. Fe-Co active sites on the graphene fence surface present 50.1% light olefin selectivity, while the spatial Fe-Co nanoparticles separated by graphene fences achieve liquefied petroleum gas of 43.6%. With the assistance of graphene fences, iron carbides and metallic cobalt can efficiently regulate C-C coupling and olefin secondary hydrogenation reactions to achieve product-selective switching between light olefins and liquefied petroleum gas. Furthermore, it also creates a precedent for CO2 direct hydrogenation to liquefied petroleum gas via a Fischer-Tropsch pathway with the highest space-time yields compared to other reported composite catalysts.

4.
Environ Res ; 242: 117715, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-37996000

RESUMO

The thermocatalytic conversion of carbon dioxide (CO2) into high value-added chemicals provides a strategy to address the environmental problems caused by excessive carbon emissions and the sustainable production of chemicals. Significant progress has been made in the CO2 hydrogenation to long chain α-olefins, but controlling C-O activation and C-C coupling remains a great challenge. This review focuses on the recent advances in catalyst design concepts for the synthesis of long chain α-olefins from CO2 hydrogenation. We have systematically summarized and analyzed the ingenious design of catalysts, reaction mechanisms, the interaction between active sites and supports, structure-activity relationship, influence of reaction process parameters on catalyst performance, and catalyst stability, as well as the regeneration methods. Meanwhile, the challenges in the development of the long chain α-olefins synthesis from CO2 hydrogenation are proposed, and the future development opportunities are prospected. The aim of this review is to provide a comprehensive perspective on long chain α-olefins synthesis from CO2 hydrogenation to inspire the invention of novel catalysts and accelerate the development of this process.


Assuntos
Alcenos , Dióxido de Carbono , Hidrogenação
5.
Angew Chem Int Ed Engl ; 62(46): e202311786, 2023 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-37735097

RESUMO

The conversion of CO2 into ethanol with renewable H2 has attracted tremendous attention due to its integrated functions of carbon elimination and chemical synthesis, but remains challenging. The electronic properties of a catalyst are essential to determine the adsorption strength and configuration of the key intermediates, therefore altering the reaction network for targeted synthesis. Herein, we describe a catalytic system in which a carbon buffer layer is employed to tailor the electronic properties of the ternary ZnOx -Fe5 C2 -Fe3 O4 , in which the electron-transfer pathway (ZnOx →Fe species or carbon layer) ensures the appropriate adsorption strength of -CO* on the catalytic interface, facilitating C-C coupling between -CHx * and -CO* for ethanol synthesis. Benefiting from this unique electron-transfer buffering effect, an extremely high ethanol yield of 366.6 gEtOH kgcat -1 h-1 (with CO of 10 vol % co-feeding) is achieved from CO2 hydrogenation. This work provides a powerful electronic modulation strategy for catalyst design in terms of highly oriented synthesis.

6.
Molecules ; 28(18)2023 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-37764410

RESUMO

The direct selective conversion of ethanol to butadiene (ETB) is a competitive and environmentally friendly process compared to the traditional crude cracking route. The acid-base properties of catalysts are crucial for the direct ETB process. Herein, we report a rationally designed multifunctional lignin-derived carbon-modulated ZnZr/SiO2 (L-ZnZr/SiO2) catalyst with suitable acid-base properties for the direct ETB reaction. A variety of characterization techniques are employed to investigate the relationship between the acid-base properties and catalytic performance of the multifunctional lignin-modulated ZnZr/SiO2 catalysts. The results revealed that the rationally additional lignin-modulated carbon enhances both the acidity and basicity of the ZnZr/SiO2 catalysts, providing a suitable acid-base ratio that boosts the direct ETB reactivity. Meanwhile, the 1% L-ZnZr/SiO2 catalyst possessed ethanol conversion and butadiene selectivity as high as 98.4% and 55.5%, respectively, and exhibited excellent catalytic stability.

7.
Chemistry ; 29(65): e202301918, 2023 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-37641166

RESUMO

Even though Fe-based catalysts have been widely employed for CO2 hydrogenation into hydrocarbons, oxygenates, liquid fuels, etc., the precise regulation of their physicochemical properties is needed to enhance the catalytic performance. Herein, under the guidance of the traditional concept in heterogeneous catalysis-confinement effect, a core-shell structured catalyst Na-Fe3 O4 @C is constructed to boost the CO2 hydrogenation performance. Benefiting from the carbon-chain growth limitation, tailorable H2 /CO2 ratio on the catalytic interface, and unique electronic property that all endowed by the confinement effect, the selectivity and space-time yield of light olefins (C2 = -C4 = ) are as high as 47.4 % and 15.9 g molFe -1  h-1 , respectively, which are all notably higher than that from the shell-less counterpart. The function mechanism of the confinement effect in Fe-based catalysts are clarified in detail by multiple characterization and density functional theory (DFT). This work may offer a new prospect for the rational design of CO2 hydrogenation catalyst.

8.
Acc Chem Res ; 56(17): 2341-2353, 2023 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-37579494

RESUMO

ConspectusC1 catalysis, which refers to the conversion of molecules with a single carbon atom, such as CO, CO2, and CH4, into clean fuels and basic building blocks for chemical industries, has built a bridge between carbon resource utilization and valuable chemical supply. With respect to the goal of carbon neutrality, C1 catalysis also plays an essential role owing to its integrated functions in the green catalytic process with fewer CO2 emissions and even direct high-value-added utilization of greenhouse gases (CO2 and CH4). However, the inert nature of the C-O or C-H bond in C1 molecules as well as uncontrollable C-C coupling render C1 catalysis challenging. The rational design of highly active catalytic materials (denoted as C1 catalysts) with strong capacities for C-O or C-H bond activation and C-C coupling by convenient nanomaterials fabrication methods to boost the catalytic performance of C1 molecule conversion, including targeted product selectivity and long-term stability, is the cornerstone of C1 catalysis.Notably, the familiar concepts in heterogeneous catalysis, such as tandem catalysis and confinement catalysis, are applicable for C1 catalysis and have been successfully used to design a C1 catalyst. Regarding the tandem catalysis concept that integrates multiple reactions in a single-pass via a bi- or multifunctional catalyst, it is promising to shed new light on the oriented conversion of C1 molecules, especially for C2+ hydrocarbon or oxygenate synthesis. The confinement effect is powerful for controlling the product distribution and enhancing activation efficiency of inert chemical bonds in C1 catalysis due to the unique reactants/intermediate adsorption and evolution behaviors on the confined catalytic interface with a special electronic environment. Moreover, metal-support interactions (MSIs), electronic properties of the active site, and catalytic engineering issues are also susceptible to the C1 molecule conversion performance. Therefore, under the guidance of basic and novel rules in heterogeneous catalysis, the innovation of catalytic materials with the aid of advanced catalytic materials fabrication techniques has always been a hot research topic in C1 catalysis.In this Account, we briefly describe the challenges in thermal-catalytic C1 molecule (mainly CO, CO2, and CH4) conversion. At the same time, the synergistic functioning of the physicochemical properties of the catalytic materials on the performance in C1 molecule conversion is highlighted. More importantly, we summarize our progress in rationally designing tailor-made C1 catalysts to enhance C1 molecule activation efficiency and targeted product selectivity via powerful nanomaterials fabrication techniques, such as traditional wet-chemistry strategies, the magnetron sputtering method, and 3D printing technology. Specifically, the ingenious capsule catalyst and ammonia pools in zeolites fabricated by a wet chemistry process possess an extraordinary effect on the transformation of CO, CO2, and CH4 molecules. Also, the sputtering method is reliable in modulating the electronic properties of metallic active sites for C1 molecule conversion, thereby tailoring the final product selectivity. Furthermore, we showcase the strong capability of metal 3D printing technology in fabricating a self-catalytic reactor, by which the functions of the reaction field and nanoscale active sites are well integrated. Finally, we predict the future research opportunities in highly efficient C1 catalyst design with the assistance of clever nanomaterials fabrication techniques.

9.
RSC Adv ; 13(32): 22493-22502, 2023 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-37497091

RESUMO

A series of Cu-ZnO-Al2O3 catalysts (CZA) were prepared by glucose pretreatment and applied for methanol synthesis from CO2 hydrogenation. The advantages of the glucose pretreatment and the effects of glucose content were investigated by XRD, N2 physisorption, SEM, N2O chemisorption, CO2-TPD, H2-TPR, TG, and XPS characterization techniques. The influence of glucose pretreatment on the average Cu particle size and the interaction between different components, as well as the effects of the amount of glucose on the Cu specific surface area, the ratio of Cu0/Cu+ and the performance of the catalysts were discussed. The results showed that the catalysts prepared by glucose pretreatment increased the number of basic sites and had a significant advantage in methanol yield. The optimum content of glucose was beneficial to improve the catalytic performance of the CZA catalyst. The maximum space-time yield of methanol was obtained by 2 wt% glucose pretreatments at 200 °C, which was 57.0 g kg-1 h-1.

10.
Chemistry ; 29(40): e202301135, 2023 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-37160742

RESUMO

Even though the direct hydrogenation of CO2 into aromatics has been realized via a methanol-mediated pathway and multifunctional catalyst, few works have been focused on the simultaneously rational design of each component in multifunctional catalyst to improve the performance. Also, the structure-function relationship between aromatics synthesis performance and the different catalytic components (reducible metal oxide and acidic zeolite) has been rarely investigated. Herein, we increase the oxygen vacancy (Ov ) density in reducible Cr2 O3 by sequential carbonization and oxidation (SCO) treatments of Cr-based metal-organic frameworks. Thanks to the enriched Ov , Cr2 O3 -based catalyst affords high methanol selectivity of 98.1 % (without CO) at a CO2 conversion of 16.8 % under high reaction temperature (350 °C). Furthermore, after combining with the acidic zeolite H-ZSM-5, the multifunctional catalyst realizes the direct conversion of CO2 into aromatics with conversion and selectivity as high as 25.4 % and 80.1 % (without CO), respectively. The property of acid site in H-ZSM-5, especially the Al species that located at the intersection of straight and sinusoidal channels, plays a vital role in enhancing the aromatics selectivity, which can be precisely controlled by varying the hydrothermal synthesis conditions. Our work provides a synergistic strategy to boost the aromatics synthesis performance from CO2 hydrogenation.

11.
ChemSusChem ; 16(17): e202300418, 2023 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-37096401

RESUMO

Cu2 O has great advantages for CO2 electroreduction to C2 products, of which the activity and selectivity are closely related to its crystal facets. In this work, density functional theory calculation indicated that the (110) facets of Cu2 O had a lower energy barrier for the C-C coupling compared to the (100) and (111) facets. Therefore, Cu2 O(110) facets were successfully synthesized with the assistance of trace amounts of the ionic liquid 1-butyl-3-methylimidazolium ([Bmim]BF4 ) by a sample wet-chemical method. A high faradaic efficiency of 71.1 % and a large current density of 265.1 mA cm-2 toward C2 H4 and C2 H5 OH were achieved at -1.1 V (vs. reversible hydrogen electrode) in a flow cell. The in situ and electrochemical analysis indicated that it possessed the synergy effects of strong adsorption of *CO2 and *CO, large active area, and excellent conductivity. This study provided a new way to enhance the C2 selectivity of CO2 electroreduction on Cu2 O by crystal structure engineering.

12.
J Colloid Interface Sci ; 641: 861-874, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36966575

RESUMO

Although Prussian blue and its analogs (PB/PBAs) have open framework structures, large surface areas, uniform metal active sites, and tunable compositions, and have been investigated for a long time, owing to their unfavorable visible light responsiveness, they rarely been reported in photocatalysis. This largely limits their applications in solar-to-chemical energy conversion. Here, a continuous-evolution strategy was conducted to convert the poor-performance NiCo PBA (NCP) toward high-efficiency complex photocatalytic nanomaterials. First, chemical etching was performed to transform raw NCP (NCP-0) to hollow-structured NCP (including NCP-30, and NCP-60) with enhanced diffusion, penetration, mass transmission of reaction species, and accessible surface area. Then, the resultant hollow NCP-60 frameworks were further converted into advanced functional nanomaterials including CoO/3NiO, NiCoP nanoparticles, and CoNi2S4 nanorods with a considerably improved photocatalytic H2 evolution performance. The hollow-structured NCP-60 particles exhibit an enhanced H2 evolution rate (1.28 mol g-1h-1) compared with the raw NCP-0 (0.64 mol g-1h-1). Furthermore, the H2 evolution rate of the resulting NiCoP nanoparticles reached 16.6 mol g-1h-1, 25 times that of the NCP-0, without any cocatalysts.

13.
ACS Omega ; 7(49): 44951-44961, 2022 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-36530332

RESUMO

This research aims to investigate steam biomass gasification in a pilot horizontal gasifier using rubber wood pellets (RWPs) and eucalyptus wood chips (EWCs) for producing syngas with an H2/CO ratio range of 1.8 to 2.3 for Fischer-Tropsch synthesis. The study was divided into two parts. One was carried out in a lab-scale reactor to determine the effect of temperature and CaO on the gas product composition and the efficiency of tar removal. Another part was determined by investigating the effect of the steam/biomass (S/B) ratio on the produced H2/CO ratios in the pilot horizontal gasifier, which used the optimum conditions of temperature and % loading of CaO for tar removal according to the optimal conditions from the lab-scale gasifier. The lab-scale gasifier results showed that H2 and CO2 increased with temperature due to primary and secondary water gas reactions and hydrocarbon reforming reactions. The water gas shift and hydrocarbon reforming reaction depressed the CO and CH4 contents with increasing temperature, respectively. The optimum gasifying temperature was 900 °C, which obtained H2/CO ratios of 1.8 for both RWPs and EWCs. The tar yield decreased with increasing temperature and was less than 0.2 wt % when using CaO as a tar-cracking catalyst. The operation of the pilot horizontal gasifier at the operating condition of 900 °C and a S/B ratio of 0.5 using 0.2 wt % loading of CaO for tar removal also produced a H2/CO ratio of 2.0. The supply of an external heat source stabilized the gasifying temperature, resulting in a stable syngas composition and production rate of 2.5 and 2.7 kg/h with H2/CO ratios of 1.8 and 1.9 for the RWPs and EWCs, respectively. In summary, the horizontal gasifier is another effective designed gasifier that showed high-performance operation.

14.
ACS Cent Sci ; 8(8): 1047-1062, 2022 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-36032758

RESUMO

Syngas conversion can play a vital role in providing energy and chemical supplies while meeting environmental requirements as the world gradually shifts toward a net-zero. While prospects of this process cannot be doubted, there is a lingering challenge in distinct product selectivity over the bulk transitional metal catalysts. To advance research in this respect, composite catalysts comprising traditional metal catalysts and zeolites have been deployed to distinct product selectivity while suppressing side reactions. Zeolites are common but highly efficient materials used in the chemical industry for hydroprocessing. Combining the advantages of zeolites and some transition metal catalysts has promoted the catalytic production of various hydrocarbons (e.g., light olefins, aromatics, and liquid fuels) and oxygenates (e.g., methanol, dimethyl ether, formic acid, and higher alcohols) from syngas. In this outlook, a thorough revelation on recent progress in syngas conversion to various products over metal-zeolite composite catalysts is validated. The strategies adopted to couple the metal species and zeolite material into a composite as well as the consequential morphologies for specific product selectivity are highlighted. The key zeolite descriptors that influence catalytic performance, such as framework topologies, proximity and confinement effects, acidities and cations, pore systems, and particle sizes are discussed to provide a deep understanding of the significance of zeolites in syngas conversion. Finally, an outlook regarding challenges and opportunities for syngas conversion using zeolite-based catalysts to meet emerging energy and environmental demands is also presented.

15.
Chemistry ; 28(59): e202201783, 2022 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-35851966

RESUMO

The non-petroleum synthesis route of ethanol from syngas (H2 +CO) with methyl acetate (MA) as the core intermediate product has been confirmed as an excellent industrialization route for high purity ethanol production. However, as the central part of this tandem-catalysis path, the carbonylation of dimethyl ether (DME) to MA is limited by the undesirable catalytic activity and stability of zeolite catalysts. Herein, a facile inhibitor-assisted strategy was developed for constructing self-assembled nano-Mordenite (nano-MOR) zeolites without using any expensive or complex template. A nano-filamentous MOR zeolite with only 70 nm crystal diameter was successfully synthesized by selectively controlling the crystal growth orientation with a specific inhibitor. The catalytic performance of self-assembled nano-MOR catalysts was remarkably outstanding in DME carbonylation reaction. The highest Space-Time Yield (STY) of MA was achieved over Nanofilament MOR (NF-MOR), which was significantly improved comparing with that of the traditional Ellipsoid-MOR (ES-MOR) [3780 mmol/(kg ⋅ h) vs. 1368 mmol/(kg ⋅ h)]. One-step ethanol synthesis was realized by combining the MOR catalyst and an innovative self-reduced Cu-ZnO/SiO2 (CZ/SiO2 ) catalyst in a rationally designed dual-bed catalysis system. Adopting the tailor-made NF-MOR&CZ/SiO2 combination, it obtained the highest STY of ethanol, about 4 times of the conventional ES-MOR&CZ combination [1800 mmol/(kg ⋅ h) vs. 476 mmol/(kg ⋅ h)]. The present self-assembled nano-MOR zeolites synthetic strategy opens a new way for the fabrication of high-performance zeolites for practical industrial applications in catalytic conversions of one-carbon (C1) small molecules to high value-added chemicals.

16.
Chem Soc Rev ; 51(13): 5606-5659, 2022 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-35705080

RESUMO

Ethanol, as one of the important bulk chemicals, is widely used in modern society. It can be produced by fermentation of sugar, petroleum refining, or conversion of syngas (CO/H2). Among these approaches, conversion of syngas to ethanol (STE) is the most environmentally friendly and economical process. Although considerable progress has been made in STE conversion, control of CO activation and C-C growth remains a great challenge. This review highlights recent advances in the routes and catalysts employed in STE technology. The catalyst designs and pathway designs are summarized and analysed for the direct and indirect STE routes, respectively. In the direct STE routes (i.e., one-step synthesis of ethanol from syngas), modified catalysts of methanol synthesis, modified catalysts of Fischer-Tropsch synthesis, Mo-based catalysts, noble metal catalysts and multifunctional catalysts are systematically reviewed based on their catalyst designs. Further, in the indirect STE routes (i.e., multi-step processes for ethanol synthesis from syngas via methanol/dimethyl ether as intermediates), carbonylation of methanol/dimethyl ether followed by hydrogenation, and coupling of methanol with CO to form dimethyl oxalate followed by hydrogenation, are outlined according to their pathway designs. The goal of this review is to provide a comprehensive perspective on STE technology and inspire the invention of new catalysts and pathway designs in the near future.


Assuntos
Etanol , Metanol , Catálise , Hidrogenação , Metais , Metanol/metabolismo
17.
Nat Commun ; 13(1): 935, 2022 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-35177629

RESUMO

Reduction process is a key step to fabricate metal-zeolite catalysts in catalytic synthesis. However, because of the strong interaction force, metal oxides in zeolites are very difficult to be reduced. Existing reduction technologies are always energy-intensive, and inevitably cause the agglomeration of metallic particles in metal-zeolite catalysts or destroy zeolite structure in severe cases. Herein, we disclose that zeolites after ion exchange of ammonium have an interesting and unexpected self-reducing feature. It can accurately control the reduction of metal-zeolite catalysts, via in situ ammonia production from 'ammonia pools', meanwhile, restrains the growth of the size of metals. Such new and reliable ammonia pool effect is not influenced by topological structures of zeolites, and works well on reducible metals. The ammonia pool effect is ultimately attributed to an atmosphere-confined self-regulation mechanism. This methodology will significantly promote the fabrication for metal-zeolite catalysts, and further facilitate design and development of low-cost and high-activity catalysts.

18.
Chem Sci ; 14(1): 171-178, 2022 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-36605740

RESUMO

Catalytic conversion of CO2 to long-chain hydrocarbons with high activity and selectivity is appealing but hugely challenging. For conventional bifunctional catalysts with zeolite, poor coordination among catalytic activity, CO selectivity and target product selectivity often limit the long-chain hydrocarbon yield. Herein, we constructed a singly cobalt-modified iron-based catalyst achieving 57.8% C5+ selectivity at a CO2 conversion of 50.2%. The C5+ yield reaches 26.7%, which is a record-breaking value. Co promotes the reduction and strengthens the interaction between raw CO2 molecules and iron species. In addition to the carbide mechanism path, the existence of Co3Fe7 sites can also provide sufficient O-containing intermediate species (CO*, HCOO*, CO3 2*, and ) for subsequent chain propagation reaction via the oxygenate mechanism path. Reinforced cascade reactions between the reverse water gas shift (RWGS) reaction and chain propagation are achieved. The improved catalytic performance indicates that the KZFe-5.0Co catalyst could be an ideal candidate for industrial CO2 hydrogenation catalysts in the future.

19.
Nat Commun ; 12(1): 7209, 2021 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-34893618

RESUMO

The rational design of high-temperature endurable Cu-based catalysts is a long-sought goal since they are suffering from significant sintering. Establishing a barrier on the metal surface by the classical strong metal-support interaction (SMSI) is supposed to be an efficient way for immobilizing nanoparticles. However, Cu particles were regarded as impossible to form classical SMSI before irreversible sintering. Herein, we fabricate the SMSI between sputtering reconstructed Cu and flame-made LaTiO2 support at a mild reduction temperature, exhibiting an ultra-stable performance for more than 500 h at 600 °C. The sintering of Cu nanoparticles is effectively suppressed even at as high as 800 °C. The critical factors to success are reconstructing the electronic structure of Cu atoms in parallel with enhancing the support reducibility, which makes them adjustable by sputtering power or decorated supports. This strategy will extremely broaden the applications of Cu-based catalysts at more severe conditions and shed light on establishing SMSI on other metals.

20.
Nanoscale ; 13(44): 18507-18519, 2021 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-34730159

RESUMO

As important artificial photosynthesis, the construction of core-shell heterojunction materials is considered to be one of the effective strategies for designing highly active photocatalysts. Here, the Step-scheme (S-scheme) heterojunction photocatalyst is firmly grown by in situ phosphating. The calcination method uses MoO3 nanoparticles as the substrate, and the surface of MoO3 is phosphatized and etched gradually from the outside to the inside using the phosphine gas. The introduced phosphorus atoms can replace MoO3 oxygen atoms to form Mo-P bonds to generate molybdenum phosphide. The interface interaction dominated by chemical bonds has a stronger interface interaction force, which can promote the interface charge transfer leading to optimizing the MoP@MoO3 core-shell composite material, adjusting the quality of sodium hypophosphite, and phosphating MoO3 to varying degrees, producing the best hydrogen production H2 evolution rate is 10 000.02 µmol h-1 g-1. Density functional theory (DFT) calculations and a series of experiments were used to determine the S-scheme charge transfer mechanism in MoP@MoO3. This design provides a new idea for the introduction of surface-active sites and the construction of mixed anion photocatalysts. At the same time, a new design scheme is provided for the in situ construction of S-scheme interface heterojunction materials.

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