Chemical and spatial dual-confinement engineering for stable Na-S batteries with approximately 100% capacity retention.

Sodium-sulfur (Na-S) batteries are attracting intensive attention due to the merits like high energy and low cost, while the poor stability of sulfur cathode limits the further development. Here, we report a chemical and spatial dual-confinement approach to improve the stability of Na-S batteries. It refers to covalently bond sulfur to carbon at forms of C-S/N-C=S bonds with high strength for locking sulfur. Meanwhile, sulfur is examined to be S1-S2 small species produced by thermally cutting S8 large molecules followed by sealing in the confined pores of carbon materials. Hence, the sulfur cathode achieves a good stability of maintaining a high-capacity retention of 97.64% after 1000 cycles. Experimental and theoretical results show that Na+ is hosted via a coordination structure (N···Na···S) without breaking the C-S bond, thus impeding the formation and dissolution of sodium polysulfide to ensure a good cycling stability. This work provides a promising method for addressing the S-triggered stability problem of Na-S batteries and other S-based batteries.

Interfacial Electron Engineering of PdSn-NbN/C for Highly Efficient Cleavage of the C-C Bonds in Alkaline Ethanol Electrooxidation.

The splitting of the C-C bonds of ethanol remains a key issue to be addressed, despite tremendous efforts made over the past several decades. This study highlights the enhancement mechanism of inexpensive NbN-modified Pd1 Sn3 -NbN/C towards the C-C bonds cleavage for alkaline ethanol oxidation reaction (EOR). The optimal Pd1 Sn3 -NbN/C delivers a catalytic activity up to 43.5 times higher than that of commercial Pd/C and high carbonate selectivity (20.5%) toward alkaline EOR. Most impressively, the Pd1 Sn3 -NbN/C presents good durability even after 25 200 s of chronoamperometric testing. The enhanced catalytic performance is mainly due to the interfacial interaction between PdSn and NbN, demonstrated by multiple structural characterization results. In addition, in situ ATR-SEIRAS (Attenuated total reflection-surface enhanced infrared absorption spectroscopy) results suggest that NbN facilitates the C-C bonds cleavage towards the alkaline EOR, followed by the enhanced OH adsorption to promote the subsequent oxidation of C1 intermediates after doping Sn. DFT (density functional theory) calculations indicate that the activation barriers of the C-H bond cleavage in CH3 CH2 OH, CH3 CHOH, CH3 CHO, CH3 CO, CH2 CO, and the C-C bond cleavage in CH3 CO, CH2 CO, CHCO are evidently reduced and the removal of adsorbed CH3 CO and CO becomes easier on the PdSn-NbN/C catalyst surface.

Metal-Organic Framework Derived Bi-O-Sn/C Nanostructure: Tailoring the Adsorption Site of Dominant Intermediate for Highly Efficient CO2 Electroreduction to Formate.

Electrochemical CO2 reduction into high-value-added formic acid/formate is an attractive strategy to mitigate global warming and achieve energy sustainability. However, the adsorption energy of most catalysts for the key intermediate *OCHO is usually weak, and how to rationally optimize the adsorption of *OCHO is challenging. Here, an effective Bi-Sn bimetallic electrocatalyst (Bi1 -O-Sn1 @C) where a Bi-O-Sn bridge-type nanostructure is constructed with O as an electron bridge is reported. The electronic structure of Sn is precisely tuned by electron transfer from Bi to Sn through O bridge, resulting in the optimal adsorption energy of intermediate *OCHO on the surface of Sn and the enhanced activity for formate production. Thus, the Bi1 -O-Sn1 @C exhibits an excellent Faradaic efficiency (FE) of 97.7% at -1.1 V (vs RHE) for CO2 reduction to formate (HCOO- ) and a high current density of 310 mA cm-2 at -1.5 V, which is one of the best results catalyzed by Bi- and Sn-based catalysts reported previously. Impressively, the FE exceeds 93% at a wide potential range from -0.9 to -1.4 V. In-situ ATR-FTIR, in-situ Raman, and DFT calculations confirm the unique role of the bridge-type structure of Bi-O-Sn in highly efficient electrocatalytic reduction of CO2 into formate.

A density functional theory study on the mechanism of toluene from dimethylcyclopentane catalyzed by the [GaH]2+ active site of Ga-ZSM-5.

The ONIOM (ωb97xd/6-31G(d,p):pm6) method was used to study the reaction mechanism of dimethylcyclopentane to toluene by the [GaH]2+ active site of Ga-ZSM-5. The results showed that the rate-determining step in the dimethylcyclopentane aromatization process is the ring expansion process. Compared to those of methylcyclopentane to benzene (D. D. Zhang, H. Y. Liu, L. X. Ling, H. R. Zhang, R. G. Zhang, P. Liu and B. J. Wang, Phys. Chem. Chem. Phys., 2021, 23, 10988-11003.), the free energy barriers of dimethylcyclopentane to toluene are significantly decreased, indicating that toluene is easier to produce than benzene, which confirmed the experimental results that a higher proportion of toluene than benzene is produced in the MTA process.

Boosting Low-Temperature CO2 Hydrogenation over Ni-based Catalysts by Tuning Strong Metal-Support Interactions.

Rational design of low-cost and efficient transition-metal catalysts for low-temperature CO2 activation is significant and poses great challenges. Herein, a strategy via regulating the local electron density of active sites is developed to boost CO2 methanation that normally requires >350 °C for commercial Ni catalysts. An optimal Ni/ZrO2 catalyst affords an excellent low-temperature performance hitherto, with a CO2 conversion of 84.0 %, CH4 selectivity of 98.6 % even at 230 °C and GHSV of 12,000 mL g-1 h-1 for 106 h, reflecting one of the best CO2 methanation performance to date on Ni-based catalysts. Combined a series of in situ spectroscopic characterization studies reveal that re-constructing monoclinic-ZrO2 supported Ni species with abundant oxygen vacancies can facilitate CO2 activation, owing to the enhanced local electron density of Ni induced by the strong metal-support interactions. These findings might be of great aid for construction of robust catalysts with an enhanced performance for CO2 emission abatement and beyond.

Partial Sulphidation to Regulate Coordination Structure of Single Nickel Atoms on Graphitic Carbon Nitride for Efficient Solar H2 Evolution.

To develop a non-precious highly efficient cocatalyst to replace Pt on graphitic carbon nitride (g-C3 N4 ) for solar H2 production is great significant, but still remains a huge challenge. The emerging single-atom catalyst presents a promising strategy for developing highly efficient non-precious cocatalyst owing to its unique adjustability of local coordination environment and electronic structure. Herein, this work presents a facile approach to achieve single Ni sites (Ni1 -N2 S) with unique local coordination structure featuring one Ni atom coordinated with two nitrogen atoms and one sulfur atom, confirmed by high-angle annular dark-field scanning transmission electron microscopy, X-ray absorption spectroscopy, and density functional theory calculation. Thanks to the unique electron structure of Ni1 -N2 S sites, the 1095 µmol g-1 h-1 of high H2 evolution rate with 4.1% of apparent quantum yield at 420 nm are achieved. This work paves a pathway for designing a highly efficient non-precious transition metal cocatalyst for photocatalytic H2 evolution.

Catalytic Decomposition Mechanism of PH3 on 3DCuO/C and High Value Utilization of Deactivated Catalysts.

With the widespread application of lithium iron phosphate batteries, the production capacity of the yellow phosphorus industry has increased sharply, and the treatment of the highly toxic by-product PH3 is facing severe challenges. In this study, a 3D copper-based catalyst (3DCuO/C) that can efficiently decompose PH3 at low temperatures and low oxygen concentrations is synthesized. The PH3 capacity is up to 181.41 mg g-1 , which is superior to that previously reported in the literature. Further studies indicated that the special 3D structure of 3DCuO/C induces oxygen vacancies on the surface of CuO, which is beneficial to the activation of O2 , and then promotes the adsorption and dissociation of PH3 . The doping of P after dissociation determines the formation of Cu-P, and the eventual conversion to Cu3 P leads to the deactivation of CuO active sites. More strikingly, due to the appearance of Cu3 P, the deactivated De-3DCuO/C (Cu3 P/C) exhibited significant activity in the photocatalytic degradation of rhodamine B and photocatalytic oxidation of Hg0 (gas) and can also be a candidate as an anode material for Li batteries after modification, which will provide a more thorough and economical treatment scheme for deactivated catalysts.

The effect of introducing Ga on the ZSM-5-catalyzed methanol to aromatics reaction: taking methylcyclopentane to benzene as an example.

Naphthenes are key intermediates in the formation of aromatic compounds during the methanol to aromatics (MTA) reaction, and the dehydrogenation process is more important than the hydrogen transfer process. Theoretical studies were performed to investigate the methylcyclopentane, which represents a naphthene, to benzene MTA process catalyzed by ZSM-5 before and after introducing Ga, showing that Ga-ZSM-5 was more favorable for carrying out the reaction than two H-type ZSM-5 (H-Z1 and H-Z2) models. H-Z1 and H-Z2 are favorable for the transfer of H during ring expansion reactions and the reformation of Brønsted acids, but the dehydrogenation reactions involving H-Z1 and H-Z2 require high free-energy barriers to be overcome. Although introducing Ga to ZSM-5 is not conducive to the transfer of H after dehydrogenation, it can reduce the extremely high dehydrogenation free-energy barrier compared with H-Z1 and H-Z2; this is mainly because Ga at dehydrogenation active centers, [GaH]2+, can accept electrons and donate them to the H atoms of [GaH]2+, giving H negative charge and making it easy to combine with positive B-acid H atoms that come from methylcyclopentane, cyclohexene, and cyclohexadiene to produce H2. Also, analysis of the transition state structures of all DH processes shows that Ga-ZSM-5 is more favorable for promoting the combination of H to produce H2 than H-Z1 and H-Z2.

Catalytic performance of Pdn (n = 1, 2, 3, 4 and 6) clusters supported on TiO2-V for the formation of dimethyl oxalate via the CO catalytic coupling reaction: a theoretical study.

The formation of dimethyl oxalate (DMO) via CO catalytic coupling on a series of catalysts including Pdn (n = 1, 2, 3, 4 and 6) clusters loaded on TiO2-V has been explored by density functional theory (DFT) calculation. The results show that different Pdn clusters have a remarkable influence on DMO formation. The Pd1/TiO2-V catalyst is not suitable for the CO catalytic coupling reaction since CO is easily bound to the O atom on the surface of TiO2-V leading to the formation of CO2. The activity of four catalysts complies with the following order of Pd4/TiO2-V > Pd6/TiO2-V > Pd2/TiO2-V > Pd3/TiO2-V by comparing the activation energy barriers of the rate-determining steps in the optimal paths. Charge analysis implies that less charge is transferred from the Pd4/TiO2-V and Pd6/TiO2-V catalysts to CO than on the other catalysts, which leads to the relatively weak adsorption of CO, and therefore CO has a greater tendency to react with other species on the surface. In addition, Pd6/TiO2-V also exhibits relatively higher selectivity toward DMO than the other three catalysts. Therefore, Pd6 is regarded as a suitable cluster, which is supported on TiO2-V demonstrating high catalytic activity and selectivity to DMO.

Cost-effective promoter-doped Cu-based bimetallic catalysts for the selective hydrogenation of C2H2 to C2H4: the effect of the promoter on selectivity and activity.

In order to probe into the effect of the promoter on the selectivity and activity towards C2H4 formation in the selective hydrogenation of C2H2 over cost-effective Cu-based bimetallic catalysts, different metal promoter M-modified Cu catalysts including Ni, Ag, Au, Pt, Pd and Rh have been employed to fully investigate the selective hydrogenation of C2H2 using density functional theory calculations together with microkinetic modeling. The results show that the adsorption ability of C2H2 is far stronger than that of C2H4 on different Cu-based catalysts, which favors the activation and hydrogenation of C2H2. The type of promoter obviously affects the preferable pathway of C2H2 selective hydrogenation, and ultimately alters the selectivity of the products; only on PdCu(211) and AgCu(211) surfaces, the C2H4 desorption pathway is the most favorable for gaseous C2H4 formation, suggesting that the promoter Pd or Ag has good selectivity towards C2H4 formation. The catalytic activity towards C2H4 formation follows the order PdCu(211) > PtCu(211) > NiCu(211) > RhCu(211) > AgCu(211) > AuCu(211) > Cu(211), indicating that the promoter can obviously increase the catalytic activity towards C2H4 formation compared to the Cu catalyst alone. Thus, the promoter Pd-modified Cu catalysts exhibit the highest catalytic activity and selectivity for C2H2 hydrogenation to C2H4. This work provides a method to evaluate and obtain the type of promoter with the best activity and selectivity in the selective hydrogenation of C2H2.

CO oxidative coupling to dimethyl oxalate over Pd-Me (Me = Cu, Al) catalysts: a combined DFT and kinetic study.

CO oxidative coupling to dimethyl oxalate (DMO) on Pd(111), Pd-Cu(111) and Pd-Al(111) surfaces was systematically investigated by means of density functional theory (DFT) together with periodic slab models and micro-kinetic modeling. The binding energy results show that Cu and Al can be fine substrates to stably support Pd. The favorable pathway for DMO synthesis on these catalysts starts from the formation of two COOCH3 intermediates, followed by the coupling to each other, and the catalytic activity follows the trend of Pd-Al(111) > Pd(111) > Pd-Cu(111). Additionally, the formation of DMO is far favorable than that of dimethyl carbonate (DMC) on these catalysts. The results were further demonstrated by micro-kinetic modeling. Therefore, Pd-Al bimetallic catalysts can be applied in practice to effectively enhance the catalytic performance and greatly reduce the cost. This study can help with fine-tuning and designing of high-efficient and low-cost Pd-based bimetallic catalysts.

Insights into the mechanism of the capture of CO2 by K2CO3 sorbent: a DFT study.

The adsorption and reactions of CO2 and H2O on both monoclinic and hexagonal crystal K2CO3 were investigated using the density functional theory (DFT) approach. The calculated adsorption energies showed that adsorption of H2O molecules was clearly substantially stronger on the K2CO3 surface than the adsorption of CO2, except on the (001)-1 surface of hexagonal K2CO3, where CO2 is competitively adsorbed with H2O. Carbonation reactions easily occur on pure K2CO3 and involve two parallel paths: one is where adsorbed H2O reacts with molecular CO2 in gas to form the bicarbonate, while the other is where H2O dissociates into OH and H before bicarbonate formation, and then OH reacts with gaseous CO2 to form a bicarbonate. Our results indicate that adding a support or promoter or using a special technique to expose more (001)-1 surfaces in hexagonal K2CO3 may improve the conversion of CO2 to the bicarbonate, which provides a theoretical direction for the experimental preparation of the K2CO3 sorbent to capture CO2.

Formation of C2 oxygenates and ethanol from syngas on an Fe-decorated Cu-based catalyst: insight into the role of Fe as a promoter.

In this study, the formation mechanism of C2 oxygenates and ethanol from syngas on Fe-decorated Cu bimetallic catalyst was investigated using density functional theory (DFT) calculations together with microkinetic modeling. The results showed that CH2 was the most favored monomer among all the CHx (x = 1-3) species over the FeCu bimetallic catalyst, which was more favorable than CH3OH formation. Namely, the FeCu catalyst exhibited a good selectivity toward CH2 formation instead of CH3OH formation in syngas conversion. Starting from the CH2 monomer, CH2CO and CH3CO via CO insertion into CH2 and CH2CO hydrogenation were the major products instead of C2 hydrocarbons or methane, CH3CO was successively hydrogenated to ethanol via CH3CHO and CH3CH2O intermediates. Moreover, the microkinetic modeling showed that the FeCu bimetallic catalyst had a high selectivity toward ethanol rather than methanol and methane. Further, the addition of Fe into the Cu catalyst promoted CHx formation by accelerating C-O bond cleavage, suppressed methanol formation, and facilitated C2 oxygenate formation rather than methane formation, suggesting that the synergetic effect between Fe and Cu played an important role in the formation of C2 oxygenates and ethanol. In addition, it is believed that the insights derived from this study can provide clues for the catalyst design of oxygenate synthesis and other bimetallic catalytic systems.

Insight into both coverage and surface structure dependent CO adsorption and activation on different Ni surfaces from DFT and atomistic thermodynamics.

CO adsorption and activation on Ni(100), (110) and (111) surfaces have been systematically investigated to probe the effect of coverage and surface structure on CO adsorption and activation. Herein, dispersion-corrected density functional theory calculations (DFT-D) were employed, and the related thermodynamic energies at 523 K were calculated by including the zero-point energy, thermal energy and entropic corrections; the results show that the saturated coverage of CO on the Ni(111), (100) and (110) surfaces correspond to 8/9, 9/12 and 9/9 ML, respectively. As the coverage increases, the stepwise adsorption free energies decrease on the flat (111) and (100) surfaces, whereas small changes occur on the corrugated (110) surface. CO migrates from the three-fold hollow site to the top site on the (111) surface, and from the four-fold hollow to the two-fold bridge site on the (100) surface, while all the CO molecules remain at the short-bridge site on the (110) surface. As a result, the obtained intermolecular CO-CO repulsive interactions on the flat surface are stronger than the interactions on the corrugated surface. Furthermore, the computed CO vibrational frequencies at different levels of coverage over the Ni surfaces agree well with the experimental results. On the other hand, kinetic analyses were utilized to compare the stepwise CO desorption with the dissociation at different degrees of coverage on the three Ni surfaces. CO desorption is more favorable than its dissociation at all coverage levels on the most exposed Ni(111) surface. Analogously, CO desorption becomes more favorable than its dissociation on the Ni(110) surface at higher coverage, except for coverage of 1/9 ML, in which CO desorption competes with its dissociation. However, on the Ni(100) surface, CO dissociation is more favorable than its desorption at 1/12 ML; when the coverage increases from 2/12 to 3/12 ML, equilibrium states exist between dissociation and desorption over the surface; when the coverage is greater than or equal to 4/9 ML, CO desorption becomes more favorable than dissociation. By applying the atomistic thermodynamics method, the determination of stable coverage as a function of temperature and partial pressure provides useful information, not only for surface science studies under ultrahigh vacuum conditions, but also for practical applications at high temperature and pressure in exploring reactions.

Effects of CO and CO2 on the desulfurization of H2S using a ZnO sorbent: a density functional theory study.

The density functional theory (DFT) method has been performed to study the effects of CO and CO2 on the desulfurization of H2S over a ZnO sorbent. It shows that COS is inevitably formed on the ZnO(101¯0) surface, which tends to be adsorbed onto the surface via a S-C bond binding with either a long or a short Zn-O bond. Potential energy profiles for the COS formation via reactions between H2S and CO, and H2S and CO2 on the ZnO(101¯0) surface have been constructed. In the presence of CO, the dissociated active S of H2S reacting with CO leads to the formation of COS, and the activation energy of the rate-determining step is 87.7 kJ mol(-1). When CO2 is present, the linear CO2 is first transferred to active CO2 in a triplet state, and then combines with active S to form COS with the highest energy barrier of 142.4 kJ mol(-1). Rate constants at different temperatures show that the formation of COS via the reaction of CO and H2S is easier than that of CO2 and H2S over the ZnO surface.

Insight into the mechanism about the initiation, growth and termination of the C-C chain in syngas conversion on the Co(0001) surface: a theoretical study.

The initiation, growth and termination mechanism of the C-C chain from syngas on the Co(0001) surface have been investigated using DFT calculations. Our results show that CHx (x = 1-3) formation is easier than CH3OH, both CH and CH2 species are the dominant forms of CHx (x = 1-3), both CH and CH2 species dominantly interact with CHO to form CHCHO and CH2CHO, and realizes the initial C-C chain formation. Then, CHCHO and CH2CHO prefer to be successively hydrogenated to CH3CHO, followed by C-O bond cleavage to give CH3CH; subsequently, CHO insertion into CH3CH can realize the further chain growth to form CH3CHCHO, followed by dissociation and hydrogenation to give CH3CHCH and CH3CH2CHO, respectively; further, CH3CHCH hydrogenation or CH3CH2CHO dissociation via the C-O bond cleavage can form the CH3CH-like species CH3CH2CH intermediate. Thus, the mechanism of a C-C chain growth cycle has been proposed that starts from a CH3CH2CH intermediate, followed by repeating the above C-C chain growth cycle via CH3CH intermediates, and the C-C chain growth to higher C2+ hydrocarbons and oxygenates can be realized, in which RCH2CH prefers to interact with CHO to form RCH2CHCHO, followed by its C-O bond cleavage and its hydrogenation to form R'CHCH (R' = RCH2) and R'CH2CHO (R' = RCH2), respectively, where R'CHCH hydrogenation and C-O bond cleavage of R'CH2CHO will produce R'CH2CH. Moreover, aldehyde intermediates R'CH2CHO are expected to undergo C-O bond cleavage to five R'CH2CH (R' = RCH2) rather than its desorption and its hydrogenation to alcohol. The C-C chain termination occurs at three possible positions along the growth cycle: R'CH2CHO desorption, R'CHCH with successive hydrogenation steps to alkanes or alkenes, and R'CH2CH hydrogenation to alkanes, in which the relative importance of termination of R'CHCH and R'CH2CH with hydrocarbons will depend strongly on the hydrogen coverage on the metal surface. The results of this work not only illustrate the initiation, growth and termination mechanism of the C-C chain involved in FTS on the Co(0001) surface, but also serve as a basis for the rational design of other Co surfaces toward desirable higher hydrocarbons or oxygenates.

A Ce-CuZn catalyst with abundant Cu/Zn-OV-Ce active sites for CO2 hydrogenation to methanol.

CO2 hydrogenation to chemicals and fuels is a significant approach for achieving carbon neutrality. It is essential to rationally design the chemical structure and catalytic active sites towards the development of efficient catalysts. Here we show a Ce-CuZn catalyst with enriched Cu/Zn-OV-Ce active sites fabricated through the atomic-level substitution of Cu and Zn into Ce-MOF precursor. The Ce-CuZn catalyst exhibits a high methanol selectivity of 71.1% and a space-time yield of methanol up to 400.3 g·kgcat-1·h-1 with excellent stability for 170 h at 260 °C, comparable to that of the state-of-the-art CuZnAl catalysts. Controlled experiments and DFT calculations confirm that the incorporation of Cu and Zn into CeO2 with abundant oxygen vacancies can facilitate H2 dissociation energetically and thus improve CO2 hydrogenation over the Ce-CuZn catalyst via formate intermediates. This work offers an atomic-level design strategy for constructing efficient multi-metal catalysts for methanol synthesis through precise control of active sites.

Ethane Dehydrogenation over the Core-Shell Pt-Based Alloy Catalysts: Driven by Engineering the Shell Composition and Thickness.

Pt-based catalysts as the commercial catalysts in ethane dehydrogenation (EDH) face one of the main challenges of realizing the balance between coke formation and catalytic activity. In this work, a strategy to drive the catalytic performance of EDH on Pt-Sn alloy catalysts is proposed by rationally engineering the shell surface structure and thickness of core-shell Pt@Pt3Sn and Pt3Sn@Pt catalysts from a theoretical perspective. Eight types of Pt@Pt3Sn and Pt3Sn@Pt catalysts with different Pt and Pt3Sn shell thicknesses are considered and compared with the industrially used Pt and Pt3Sn catalysts. Density functional theory (DFT) calculations completely describe the reaction network of EDH, including the side reactions of deep dehydrogenation and C-C bond cracking. Kinetic Monte Carlo (kMC) simulations reveal the influences of the catalyst surface structure, experimentally related temperatures, and reactant partial pressures. The results show that CHCH* is the main precursor for coke formation, and Pt@Pt3Sn catalysts generally have higher C2H4(g) activity and lower selectivity compared to those of Pt3Sn@Pt catalysts, which is attributed to the unique surface geometrical and electronic properties. 1Pt3Sn@4Pt and 1Pt@4Pt3Sn are screened out as catalysts exhibiting excellent performance; especially, the 1Pt3Sn@4Pt catalyst has much higher C2H4(g) activity and 100% C2H4(g) selectivity compared to those of 1Pt@4Pt3Sn and the widely used Pt and Pt3Sn catalysts. The two descriptors C2H5* adsorption energy and reaction energy of its dehydrogenation to C2H4* are proposed to qualitatively evaluate the C2H4(g) selectivity and activity, respectively. This work facilitates a valuable exploration for optimizing the catalytic performance of core-shell Pt-based catalysts in EDH and reveals the great importance of the fine control of the catalyst shell surface structure and thickness.

Precise solid-phase synthesis of CoFe@FeOx nanoparticles for efficient polysulfide regulation in lithium/sodium-sulfur batteries.

Complex metal nanoparticles distributed uniformly on supports demonstrate distinctive physicochemical properties and thus attract a wide attention for applications. The commonly used wet chemistry methods display limitations to achieve the nanoparticle structure design and uniform dispersion simultaneously. Solid-phase synthesis serves as an interesting strategy which can achieve the fabrication of complex metal nanoparticles on supports. Herein, the solid-phase synthesis strategy is developed to precisely synthesize uniformly distributed CoFe@FeOx core@shell nanoparticles. Fe atoms are preferentially exsolved from CoFe alloy bulk to the surface and then be carburized into a FexC shell under thermal syngas atmosphere, subsequently the formed FexC shell is passivated by air, obtaining CoFe@FeOx with a CoFe alloy core and a FeOx shell. This strategy is universal for the synthesis of MFe@FeOx (M = Co, Ni, Mn). The CoFe@FeOx exhibits bifunctional effect on regulating polysulfides as the separator coating layer for Li-S and Na-S batteries. This method could be developed into solid-phase synthetic systems to construct well distributed complex metal nanoparticles.

[EMmim][NTf2 ]-a Novel Ionic Liquid (IL) in Catalytic CO2 Capture and ILs' Applications.

Ionic liquids (ILs) have been used for carbon dioxide (CO2 ) capture, however, which have never been used as catalysts to accelerate CO2 capture. The record is broken by a uniquely designed IL, [EMmim][NTf2 ]. The IL can universally catalyze both CO2 sorption and desorption of all the chemisorption-based technologies. As demonstrated in monoethanolamine (MEA) based CO2 capture, even with the addition of only 2000 ppm IL catalyst, the rate of CO2 desorption-the key to reducing the overall CO2 capture energy consumption or breaking the bottleneck of the state-of-the-art technologies and Paris Agreement implementation-can be increased by 791% at 85 °C, which makes use of low-temperature waste heat and avoids secondary pollution during CO2 capture feasible. Furthermore, the catalytic CO2 capture mechanism is experimentally and theoretically revealed.