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The dynamic restructuring of Cu has been observed under electrochemical conditions, and it has been hypothesized to underlie the unique reactivity of Cu toward CO2electroreduction. Roughening is one of the key surface phenomena for Cu activation, whereby numerous atomic vacancies and adatoms form. However, the atomic structure of such surface motifs in the presence of relevant adsorbates has remained elusive. Here, we explore the chemical space of Cu surface restructuring under coverage of CO and H in realistic electroreduction conditions, by combining grand canonical DFT and global optimization techniques, from which we construct a potential-dependent grand canonical ensemble representation. The regime of intermediate and mixed CO and H coverage─where structures exhibit some elevated surface Cu─is thermodynamically unfavorable yet kinetically inevitable. Therefore, we develop a quasi-kinetic Monte Carlo simulation to track the system’s evolution during a simulated cathodic scan. We reveal the evolution path of the system across coverage space and identify the accessible metastable structures formed along the way. Chemical bonding analysis is performed on the metastable structures with elevated Cu*CO species to understand their formation mechanism. By molecular dynamics simulations and free energy calculations, the surface chemistry of the Cu*CO species is explored, and we identify plausible mechanisms via which the Cu*CO species may diffuse or dimerize. This work provides rich atomistic insights into the phenomenon of surface roughening and the structure of involved species. It also features generalizable methods to explore the chemical space of restructuring surfaces with mixed adsorbates and their nonequilibrium evolution.

Single atom electrocatalysts, with noble metal-free composition, maximal atom efficiency, and exceptional reactivity toward various energy and environmental applications, have become a research hot spot in the recent decade. Their simplicity and the isolated nature of the atomic structure of their active site have also made them an ideal model catalyst system for studying reaction mechanisms and activity trends. However, the state of the single atom active sites during electrochemical reactions may not be as simple as is usually assumed. To the contrary, the single atom electrocatalysts have been reported to be under greater influence from interfacial dynamics, with solvent and electrolyte ions perpetually interacting with the electrified active center under an applied electrode potential. These complexities render the activity trends and reaction mechanisms derived from simplistic models dubious.

Molybdenum dioxide (MoO2) has been considered as a promising hydrogen evolution reaction (HER) electrocatalyst. However, the active sites are mainly located at the edges, resulting in few active sites and poor activity in the HER. Herein, we first reported on an efficient strategy to incorporate Fe into MoO2nanosheets on Ni foam (Fe–MoO2/NF) using a rapid carbothermal shocking method (820 °C for 127 s). Notably, the different spin states between Fe and Mo atoms could lead to rich lattice dislocations in Fe–MoO2/NF, exposing abundant oxygen vacancies and the low-oxidation-state of Mo sites during the rapid Joule heating process. As tested, the catalyst exhibited superior activity with ultralow overpotentials (HER: 17 mV@10 mA cm−2; oxygen evolution reaction (OER): 310 mV@50 mA cm−2) and high OER selectivity in alkaline seawater splitting. Meanwhile, this catalyst was equipped in a home-made anion exchange membrane (AEM) seawater electrolyzer, which achieved a low energy consumption (5.5 kW h m−3). More importantly, Fe–MoO2/NF also coupled very well with a solar-driven electrolytic system and turned out a solar-to-hydrogen (STH) efficiency of 13.5%. Theoretical results also demonstrated that Fe incorporated and abundant oxygen vacancies in MoO2can distort the distance of the Mo–O bonds and regulate the electronic structure, thus optimizing the binding energy of H*/OOH* adsorption. This method can be extended to other heterogeneous spin states in MoO2-based catalysts (e.g.Ni–MoO2/NF, Co–MoO2/NF) for seawater splitting, and provide a simple, efficient and universal strategy to prepare highly-efficient MoO2-based electrocatalysts.

Boron-containing materials, such as hexagonal boron nitride (h-BN), recently shown to be active and selective catalysts for the oxidative dehydrogenation of propane (ODHP), have been shown to undergo significant surface oxyfunctionalization and restructuring. Although experimental ex situ studies have probed the change in chemical environment on the surface, the structural evolution of it under varying reaction conditions has not been established. Herein, we perform global optimization structure search with a grand canonical genetic algorithm to explore the chemical space of off-stoichiometric restructuring of the h-BN surface under ambient as well as ODHP-relevant conditions. A grand canonical ensemble representation of the surface is established, and the predicted 11B solid-state NMR spectra are consistent with previous experimental reports. In addition, we investigated the relative sliding of h-BN sheets and how it influences the surface chemistry with ab initio molecular dynamics simulations. The B–O linkages on the edges are found to be significantly strained during the sliding, causing the metastable sliding configurations to have higher reactivity toward the activation of propane and water.

In analogy to natural enzymes, an elaborated design of catalytic systems with a specifically tailored local chemical environment could substantially improve reaction kinetics, effectively combat catalyst poisoning effect and boost catalyst lifetime under unfavourable reaction conditions. Here we report a unique design of ‘Ni(OH)2-clothed Pt-tetrapods’ with an amorphous Ni(OH)2shell as a water dissociation catalyst and a proton conductive encapsulation layer to isolate the Pt core from bulk alkaline electrolyte while ensuring efficient proton supply to the active Pt sites. This design creates a favourable local chemical environment to result in acidic-like hydrogen evolution reaction kinetics with a lowest Tafel slope of 27 mV per decade and a record-high specific activity and mass activity in alkaline electrolyte. The proton conductive Ni(OH)2shell can also effectively reject impurity ions and retard the Oswald ripening, endowing a high tolerance to solution impurities and exceptional long-term durability that is difficult to achieve in the naked Pt catalysts. The markedly improved hydrogen evolution reaction activity and durability in an alkaline medium promise an attractive catalyst material for alkaline water electrolysers and renewable chemical fuel generation.

The design of active and low-cost electrocatalyst for hydrogen evolution reaction (HER) is the key to achieving a clean hydrogen energy infrastructure. The most successful design principle of hydrogen electrocatalyst is the activity volcano plot, which is based on Sabatier principle and has been used to understand the exceptional activity of noble metal and design of metal alloy catalysts. However, this application of volcano plot in designing single-atom electrocatalysts (SAEs) on nitrogen doped graphene (TM/N4C catalysts) for HER has been less successful due to the nonmetallic nature of the single metal atom site. Herein, by performing ab initio molecular dynamics simulations and free energy calculations on a series of SAEs systems (TM/N4C with TM = 3d, 4d, or 5d metals), we find that the strong charge–dipole interaction between the negatively charged *H intermediate and the interfacial H2O molecules could alter the transition path of the acidic Volmer reaction and dramatically raise its kinetic barrier, despite its favorable adsorption free energy. Such kinetic hindrance is also experimentally confirmed by electrochemical measurements. By combining the hydrogen adsorption free energy and the physics of competing interfacial interactions, we propose a unifying design principle for engineering the SAEs used for hydrogen energy conversion, which incorporates both thermodynamic and kinetic considerations and allows going beyond the activity volcano model.

Seawater electrolysis is a promising technique for H2production on a large scale. However, the electrocatalytic activity and stability will be deteriorated as the increase of salt concentrations which happened in the seawater splitting. Herein, through the electrodeposition and rapid Joule heating method, the Fe-NiO/MoO2heterostructure is designed as a highly active bifunctional electrocatalyst. During the OER possess, Fe-NiO/MoO2is reconstructed to the Fe, Mo-NiOOH with Fe and Mo co-doping. Based on the theoretical analysis, more electrons were transferred to the O atoms on the surface of Fe, Mo-NiOOH, thereby forming a more negatively charged surface. Moreover, that surface is found to repel Cl−ions while enriching H2O molecules to form a thin water layer on Fe, Mo-NiOOH surface based on molecule dynamics (MD) simulation, thereby improving the anti-corrosion capacity of Fe, Mo-NiOOH. The reconstructed Fe, Mo-NiOOH achieved an overpotential of 399 mV at 1000 mA cm−2in alkaline seawater, and the increase of overpotential for Fe, Mo-NiOOH was about 0.02 V at 500 mA cm−2from 0 M to 3 M NaCl in 1 M KOH electrolyte. For the HER, Fe-NiO/MoO2achieved an overpotential of 169 mV and 417 mV at 100 and 1000 mA cm−2in alkaline seawater, respectively, and the increase of overpotential for Fe-NiO/MoO2was about 0 mV at 500 mA cm−2from 0 M to 3 M NaCl in 1 M KOH electrolyte. This work sheds fresh light into the development of efficient electrocatalysts for salinity tolerance seawater splitting.

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The molecular catalyst/nanocarbon hybrid through π–π stacking immobilization is an emerging family of single-atom catalysts with outstanding performance in electrocatalysis, well-defined active site, and tunability at molecular level through functional group substitution. In the present work, we provide a general strategy for the rational design of molecular single-atom catalyst in the form of nickel phthalocyanine@nanocarbon (NiPc@NC) for highly efficient electroreduction of CO2to CO. We employ density functional theory (DFT) calculations and state-of-the-art electronic structure analysis to explore the mechanism and substituent effects on structural stability, redox chemistry, adsorption properties, and molecule–substrate interactions of the NiPc catalyst. We have revealed that the electron-withdrawing groups facilitate the reductive activation of the catalytic Ni center but weaken the Ni–N bond strength and make the CO desorption sluggish, while the electron-donating groups do the opposite. A substituent-dependent correlation between interaction strength and electron transfer through the interface is also revealed by noncovalent interaction analysis and electron density difference projection. On the basis of the gained insights, we apply semiempirical quantum mechanical (SQM) calculation, machine learning (ML), and genetic algorithm (GA) to screening through the chemical space of ca. 10 trillion substituted NiPc molecules under a descriptor scheme to identify promising molecular candidates for the NiPc@NC hybrid material. The best candidate from GA search outperforms the state-of-the-art catalyst in terms of stability, reduction potential (improved by 110 mV), and interaction with substrate (strengthened by 0.46 eV). Design strategies are proposed based on the top-scoring molecules from computational screening, and the workflow is highly generalizable and transferable to similar molecular systems for other applications.

A multifunctional interlayer of ZIF-7 sheets vertically grown on carbon cloth (ZIF-7@CC) was developed as efficient polysulfide barrier for lithium-sulfur batteries.

The activity of molybdenum (Mo)-based catalysts is significantly limited by the dissolution of Mo under alkaline conditions. Herein, using the dissolution of Mo in electrolysis, we firstly developed a feasible method to prepare an amorphous-crystalline MoOx/Co(OH)2interfacial electrocatalysts with high activity and corrosion resistance on nickel foam (MoOx/Co(OH)2/NF). Notably, the dissolution of Mo accelerated the self-reconstruction process to favorably generate highly active and stable Co-O-Mo6+species. Among them, high-valence Mo6+in Co-O-Mo species can accumulate a large number of electrons at the O sites, thus optimizing p-band center of O sites and enhance the hydrogen adsorption ability (ΔGH*= 0.05 eV). Meanwhile, in-situ formed MoO42-and Co(OH)2in MoOx/Co(OH)2/NF could inhibit the damage of metals ions and Cl-to O active species, and thereby enhancing its stability in electrocatalytic seawater splitting. As expected, the catalyst displayed a superior activity with ultralow overpotentials (HER: 215 mV @ 1000 mA·cm −2) and high stability for 1000 h at 500 mA·cm−2in alkaline seawater electrolytes. In all, this study can provide a new route to prepare highly-active and corrosion-resistant electrocatalysts via self-reconstruction, and further the development of industrial hydrogen production.

For the purpose of resolving issues of high production costs due to targeting intermediate products from tandem reaction systems in the isobutylene (IB) dimerization process with tert-butanol as a polymerization inhibitor, a potentially sustainable catalytic distillation (CD) process is proposed as the base case for efficient continuous diisobutylene production in this paper. This study covers the extensive design of the novel CD process with 99 wt % diisobutylene and 90 wt % oligomers as the final products, using a simulation-based optimization framework on the simulator Aspen Plus with a FORTRAN subroutine of Langmuir–Hinshelwood model for kinetics. Furthermore, the advanced heat-integrated manufacturing process by exploiting catalytic dividing wall distillation and double-effect catalytic distillation with/without vapor-recompressed heat pump (DECD-VRHP) technologies achieves a total reduction in energy and cost, compared to the base case with rigorous optimal CD. The results showed that the DECD-VRHP scheme performs better with the largest total annual cost saving of about 34% among the heat-integrated schemes compared with the CD process. Overall results demonstrate that the DECD-VRHP technology is a promising approach for the synthesis of IB dimerization.

A novel graphene framework embedded with highly dispersed Co nano-dots (Co-NDs@G) was developed as high-performance sulfur storage and immobilization material for Li-S batteries.

Lithium sulfur (Li-S) batteries demonstrate great promise for efficient energy storage systems once the lithium polysulfide (LPS) shuttling and sluggish redox kinetics can be well addressed. Herein, we developed a sea urchin-structured oxygen-deficient titanium dioxide semiconductor anchored with cobalt nano-dots (Co@TiO2-x) as a high-performance multifunctional sulfur host material for Li-S batteries. The sea urchin-structured Co@TiO2-xoffers strong structural stability and strengthened chemical interaction towards LPS. Meanwhile, the incorporation of Co nano-dots into TiO2leads to increased oxygen vacancies, which augments the electrical conduction and benefits LPS conversion acceleration as well. As a result, the oxygen vacancy-rich Co@TiO2-xcomposite exhibits excellent conductivity, strong LPS confinement and promoted sulfur electrochemical kinetics, rendering enhanced LPS shuttling inhibition and rapid redox reaction. Attributed to these features, the Co@TiO2-x/S cathode exhibits a discharge capacity of 803 mAh g-1at 1 C and a good cyclic stability upon 500 cycles with a low capacity fading rate of 0.07% per cycle. This synergistic design of conductive multifunctional LPS barrier is also promising to enlighten the material engineering in other energy storage applications.

Heterogeneous catalysis is at the heart of the chemical industry. Being able to tune and design efficient catalysts for processes of interest is of the utmost importance, and for this, a molecular-level understanding of heterogeneous catalysts is the first step and indeed a prime focus of modern catalysis research. For a long time, the single most thermodynamically stable structure of the catalytic interface attained under the reaction conditions had been envisioned as the reactive phase. However, some catalytic interfaces continue to undergo structural dynamics in the steady state, triggered by high temperatures and pressures and binding and changing reagents. Among particularly dynamic interfaces are such widely used catalysts as crystalline and amorphous surfaced supporting (sub)nanometallic clusters. Recently, it became clear that this dynamic fluxionality causes the supported clusters to populate many distinct structural and stoichiometric states under catalytic conditions. Hence, the catalytic interface should be viewed as an evolving statistical ensemble of many structures (rather than one structure). Every member in the ensemble contributes to the properties of the catalyst differently, in proportion to its probability of being populated. This new notion flips the established paradigm and calls for a new theory, new modeling approaches, operandomeasurements, and updated design strategies.

The fundamental understanding of sluggish hydrogen evolution reaction (HER) kinetics on a platinum (Pt) surface in alkaline media is a topic of considerable debate. Herein, we combine cyclic voltammetry (CV) and electrical transport spectroscopy (ETS) approaches to probe the Pt surface at different pH values and develop molecular-level insights into the pH-dependent HER kinetics in alkaline media. The change in HER Tafel slope from ∼110 mV/decade in pH 7–10 to ∼53 mV/decade in pH 11–13 suggests considerably enhanced kinetics at higher pH. The ETS studies reveal a similar pH-dependent switch in the ETS conductance signal at around pH 10, suggesting a notable change of surface adsorbates. Fixed-potential calculations and chemical bonding analysis suggest that this switch is attributed to a change in interfacial water orientation, shifting from primarily an O-down configuration below pH 10 to a H-down configuration above pH 10. This reorientation weakens the O–H bond in the interfacial water molecules and modifies the reaction pathway, leading to considerably accelerated HER kinetics at higher pH. Our integrated studies provide an unprecedented molecular-level understanding of the nontrivial pH-dependent HER kinetics in alkaline media.

A guanidine–zinc catalyst, which was nontoxic and highly active in the ring-opening polymerization (ROP) of polylactide (PLA) under industrial conditions, was assessed for its performance in the alcoholysis and aminolysis of PLA under mild conditions. Both techniques exhibited high conversion and yield in chemical recycling of PLA into value-added molecules, such as alkyl lactate and hydroxypropanamide derivatives, respectively. Notably, aminolysis was found to be significantly more efficient than alcoholysis, allowing >99% PLA conversion in less than 1 h and even selective degradation of commercialized PLA products in less than 2 h (>99% conversion). Additionally, the unprecedented approach employing diols and diamines as nucleophiles has been utilized to synthesize new, repolymerizable diol monomers, which upon reaction with dicarboxylic acids yield controllable poly(ester–amide) (PEA) structures with tunable Tgvalues ranging from 12.8 to 117.6 °C. We have developed efficient solutions for alcoholysis and aminolysis of polyesters and have successfully created a technological process to transform PLA from “old” to “new”.

Electrochemical CO2reduction reaction (CO2RR) holds great prospects for transforming CO2into useful chemicals. However, there is still a long way to go to develop effective and affordable electrochemical CO2RR catalysts. In this work, a nickel-decorated nitrogen-doped biomass-derived porous carbon (Ni@N-BPC) catalyst was developed. The catalyst displayed a high specific surface area and superior CO2RR capability. The Faraday efficiency of CO exceeds ninety percent, ranging from a broad potential of 400 mV (−0.7 to −1.1 V vs RHE), reaching approximately 98.41% at −0.9 V vs RHE. The reaction pathway of CO2conversion to CO on Ni@N-BPC was analyzed by the in situ Fourier transform infrared spectroscopy method. Based on theoretical calculations, the rate-determining step shifts from the *COOH creation to the *CO desorption step by Ni anchoring. Meanwhile, N doping modulates the electronic structure and facilitates charge transport, lowering the overpotential of the rate-determining step, thus facilitating the formation of CO. This work offers fresh perspectives on the development and utilization of biomass-derived carbon materials as CO2RR electrocatalysts.

In this work, the asphaltenes from natural Indonesia asphalt rocks were taken as raw materials for the preparation of micromesoporous enriched carbon material through pyrolysis (<500 °C) and KOH activation (<900 °C) processes. It is found that, during the pyrolysis process, the asphaltenes could be converted to noncondensable gas (36.02%), pyrolytic tar (26.57%), and residual char (37.44%). When the char was mixed together with KOH for heating, more carbons would be released due to the activation reaction, forming a carbon network. The optimal activation conditions were obtained at KOH/char ratio of 3:1 and 800 °C for 30 min. Results also show that almost all of the nitrogen atoms stay in the solid carbon during heating with little releasing to the gas or liquid products. The final obtained porous carbon materials are determined to possess a specific surface area of 1735 m2/g with rich micropores (∼2.0 nm). Instrumental characterizations show that there are abundant heteroatomic groups, including S═O, —OH, and —N═, on the activated carbon surface. Further tests by adsorption indicate that the adsorption of methylene blue on the porous carbon material is monolayer adsorption. The maximal adsorption capacity is determined to be at 556.00 mg/g, much higher than that of some commercial activated carbons. It is also indicated that the adsorption kinetics follows the pseudo-second-order kinetic model. These findings suggest that the asphaltene derived carbon material would be promising efficient adsorbents. It also sheds lights on the resourcilization of asphaltenes.

The solubility of calcium formate (form α) in four different binary solvent mixtures (methanol + water, ethanol + water, n-propanol + water, and acetone + water) from 283.15 to 323.15 K was measured by a static equilibrium method under atmospheric pressure. Results indicated that the solubility increased with the increasing temperature and water content in binary mixed solvents. The modified Apelblat equation, the combined nearly ideal binary solvent/Redlich-Kister equation, and the Jouyban–Acree equation were applied for the correlation of experimental solubility, among which the modified Apelblat equation was found to be the best fitting model for the crystallization of calcium formate (form α). This experimental data can be a fundamental guide to choose a suitable crystallization process for calcium formate in industry.

Knowledge of the interfacial structure of nanocomposite materials is a prerequisite for rational design of nanostructured photocatalysts. Herein, TiO2and g-C3N42D/2D nanocomposites were fabricated from three distinct synthetic protocols (i.e., co-calcination, solvothermal treatment and charge-induced aggregation), showing different degrees of enhancement (1.4–6.1 fold) in the visible-light induced photocatalytic hydrogen evolution reaction compared to the simple physical mixture. We propose that the interfacial Ti–O–N covalent bonding promotes the charge carrier transfer and separation more effectively than the electrostatic interaction, thus accelerating the photocatalytic H2production. Meanwhile, the exposed surface area of TiO2in the composite needs to be enlarged for deposition of the co-catalyst. This research sheds light on the rational design of hybrid nanocomposites based on earth-abundant elements for photocatalysis.

Graphitic carbon nitride (g-C3N4), a fascinating conjugated polymer, has drawn extensive attention as a metal-free, visible light-responsive photocatalyst in the areas of solar energy conversion and environmental remediation. In this work, the visible light-driven photocatalytic properties of g-C3N4were enhanced by a simple surface hydroxyl modification without damage to its composite structure. A facile hydrothermal approach was developed and systematically studied. The photocatalytic activity of hydroxyl-modified g-C3N4was evaluated with regard to the degradation of a group of refractory organic pollutants, phenol, and phenolic compounds in water under visible light. The enhancement of the photocatalytic activity of g-C3N4after surface hydroxyl modification was assessed by experimental testing results and by theoretical studies using DFT. The following merits synergistically contribute to the improvement: 1) improved adsorption energy between organic pollutants and the surface of the photocatalyst; 2) reinforced hydrophilicity of the surface of g-C3N4; 3) positively-shifted valence-band potential; and 4) improved charge separation in the formation of a heterostructure between g-C3N4and OH–C3N4. This work provides an effective method to modify a surface with hydroxyl functional groups, so as to improve its photocatalytic activity of the support.

Lateral roots (LRs) are crucial for plants to sense environmental signals in addition to water and nutrient absorption. Auxin is key for LR formation, but the underlying mechanisms are not fully understood. Here, we report that ArabidopsisERF1 inhibits LR emergence by promoting local auxin accumulation with altered distribution and regulating auxin signaling. Loss of ERF1increases LR density compared with the wild type, whereas ERF1overexpression causes the opposite phenotype. ERF1 enhances auxin transport by upregulating PIN1and AUX1, resulting in excessive auxin accumulation in the endodermal, cortical, and epidermal cells surrounding LR primordia. Furthermore, ERF1 represses ARF7transcription, thereby downregulating the expression of cell-wall remodeling genes that facilitate LR emergence. Together, our study reveals that ERF1 integrates environmental signals to promote local auxin accumulation with altered distribution and repress ARF7, consequently inhibiting LR emergence in adaptation to fluctuating environments.

In this work, co-pyrolysis of Indonesian oil sands and corn straw was investigated to evaluate the potential synergetic effect. Thermogravimetric analysis was conducted to study the thermal decomposition behaviors of individual and blend feedstocks. Improved pyrolysis characteristics and higher conversion were observed, indicating a remarkable synergetic effect. Moreover, co-pyrolysis experiments were carried out using a fixed bed reactor. The results showed that the co-pyrolysis liquid product yield was increased, while the formation of solid residue was reduced, suggesting a higher conversion. The liquid product characterization by gas chromatography–mass spectroscopy also indicated the significant synergetic effect on the liquid chemical composition. Valuable phenols and alcohols were increased, while unstable aldehydes were decreased, suggesting the chemical interactions between two feedstocks during the co-pyrolysis process. The yield improvement and compositional variations of the co-pyrolysis liquid product were beneficial for its use as fuel and chemical feedstock.

Hexagonal boron nitride (hBN) is a highly selective catalyst for the oxidative dehydrogenation of propane (ODHP) to propylene. Using a variety of ex situcharacterization techniques, the activity of the catalyst has been attributed to the formation of an amorphous boron oxyhydroxide surface layer. The ODHP reaction mechanism proceeds via a combination of surface mediated and gas phase propagated radical reactions with the relative importance of both depending on the surface-to-void-volume ratio. Here we demonstrate the unique capability of operandoX-ray Raman spectroscopy (XRS) to investigate the oxyfunctionalization of the catalyst under reaction conditions (1 mm outer diameter reactor, 500 to 550 °C, P= 30 kPa C3H8, 15 kPa O2, 56 kPa He). We probe the effect of a water cofeed on the surface of the activated catalyst and find that water removes boron oxyhydroxide from the surface, resulting in a lower reaction rate when the surface reaction dominates and an enhanced reaction rate when the gas phase contribution dominates. Computational description of the surface transformations at an atomic-level combined with high precision XRS spectra simulations with the OCEAN code rationalize the experimental observations. This work establishes XRS as a powerful technique for the investigation of light element-containing catalysts under working conditions.

The development trend of Fischer–Tropsch (F–T) technology is to develop high value-added products. The separation of linear α-olefins with low cost is an effective method. Nevertheless, the lack of thermodynamic data and the huge energy consumption are the two main problems restricting the development of the separation process. The thermodynamic data of the key components (1-dodecene and n-dodecane) in the F–T product were measured. The Wilson binary interaction parameters of the key components were obtained. Next, one traditional distillation column sequence and two dividing wall column (DWC) sequences were designed to separate the F–T heavy oil to obtain narrow fractions with different carbon numbers. Then, the obtained fractions of C10 and C12 were simulated to obtain 1-decene and 1-dodecene, respectively. There was a traditional distillation and a differential pressure thermal coupling distillation process. When separating 95.0% purity 1-decene and 1-octene, the direct DWC process and differential pressure thermal coupled distillation are an excellent combination, which can reduce the energy by 33.1% (i.e., 11,286 kW) and total annual cost by 15.9% (i.e., 3.96 × 106 $) compared with traditional distillation.

Quite different from the Canadian oil sands in oil content/composition, mineral composition, and particle size distribution, the carbonate Indonesian asphalt rocks (oil-wetted) are proven to be poorly extracted by the commercial hot-water-based extraction (7.8% bitumen recovery at 50 °C and pH 9.0). Great enhancement was obtained using multi-staged solvent extraction with four typical solvents (i.e., toluene, n-heptane, n-hexane, and cyclohexane), resulting in a cumulative bitumen recovery up to 98% at ambient conditions. After the extraction, a systematical particle sedimentation test has been conducted in the non-aqueous phase. It is found that there are oil-phase and consolidated zone with only one clear solid–liquid interface appearing in the toluene and cyclohexane solutions with high bitumen during the carbonate particle sedimentation. However, an extra “settling zone” appeared between the oil-phase and consolidated zone in n-heptane and n-hexane solutions, resulting in the appearance of two solid–liquid interfaces. A mathematical model has been proposed to describe the carbonate particle settling behaviors for both interfaces in different solvent extraction systems. The settling rates of carbonate particles in different solutions are in a descending order of n-hexane > n-heptane > toluene > cyclohexane. The equilibrium height of settled solids is found to be higher in n-hexane and n-heptane systems than those in toluene and cyclohexane systems at given conditions, which is mainly contributed to the higher bitumen components (e.g., asphaltenes) attached on the solid surfaces. A water-flooding method is finally applied to remove and recover the residual solvent from the waste solids, leading up to 93% of the residual solvent together with some residual bitumen being recovered. It is also found that increasing the wettability of residual carbonate solids by increasing extraction times is beneficial for the residual solvent recovery.

Lithium-sulfur battery is perceived as one promising next generation rechargeable battery system, in view of its high theoretical specific capacity and energy density. However, the “shuttle effect” of polysulfides and the uncontrolled growth of lithium dendrites significantly obstruct its practical application. Herein, a bifunctional separator with double-sided modification is developed to simultaneously resolve these issues, which is constructed by growing continuous cerium-based metal-organic framework-808 (Ce-MOF-808) membranes on both sides of the commercial polypropylene (PP) separator through a simple in-situgrowth method. On the cathode side, the Ce-MOF-808 membrane can play multiple roles of adsorption, selective sieving and catalytic conversion towards polysulfides, thereby effectively inhibiting their shuttle effect. On the anode side, the highly uniform pore distribution and polar groups of this MOF membrane ensure the fast and homogenous diffusion of lithium ions, endowing a stable lithium nucleation and growth in the cycles. Consequently, the Ce-MOF-808/PP separator exhibits a high initial specific capacity of 954.7 mAh g−1under 1 C with a very limited capacity fading of 0.025% in 500 cycles, and an outstanding rate capability. Moreover, the separator also ensures the stable cycling of the battery at raised sulfur loading and lean-electrolyte conditions.

The rearrangement of Cu surfaces under electrochemical conditions is known to play a key role in the surface activation for major electrocatalytic reactions. Despite the extensive experimental insights into such rearrangements, from surface-sensitive spectroscopy and microscopy, the spatial and temporal resolution of these methods is insufficient to provide an atomistic picture of the electrochemical interface. Theoretical characterization has also been challenged by the diversity of restructuring configurations, surface stoichiometry, adsorbate configurations, and the effect of the electrode potential. Here, atomistic insight into the restructuring of the electrochemical interface is gained from first principles. Cu(100) restructuring under varying applied potentials and adsorbate coverages is studied by grand canonical density functional theory and global optimization techniques, as well as ab initio molecular dynamics and mechanistic calculations. We show that electroreduction conditions cause the formation of a shifted-row reconstruction on Cu(100), induced by hydrogen adsorption. The reconstruction is initiated at 1/6 ML H coverage, when the Cu–H bonding sufficiently weakens the Cu–Cu bonds between the top- and sublayer, and further stabilized at 1/3 ML when H adsorbates fill all the created 3-fold hollow sites. The simulated scanning tunneling microscopy (STM) images of the calculated reconstructed interfaces agree with experimental in situSTM. However, compared to the thermodynamic prediction, the onsets of reconstruction events in the experiment occur at more negative applied voltages. This is attributed to kinetic effects in restructuring, which we describe via different statistical models, to produce the potential- and pH-dependent surface stability diagram. This manuscript provides rich atomistic insight into surface restructuring in electroreduction conditions, which is required for the understanding and design of Cu-based materials for electrocatalytic processes. It also offers the methodology to study the problem of in situelectrode reconstruction.

A layer of Cu2O crystal film and ZnO nanoparticles doped with bimetallic Mo and Fe were successively grown on the surface of a copper mesh, which was applied in a liquid membrane photoreaction apparatus for photocatalytic nitrogen reduction reaction (PNRR). The characterization results indicate that the excellent ammonia yield benefits mainly from the synergistic effect of bimetallic doping, moderate oxygen vacancies (OVs), and p-n heterojunction. Surface defects caused by in situ doping of Mo and Fe ions act as active centers to capture and migrate electrons from the catalyst to adsorbed N2molecule. With the introduction of bimetallic ions, the formation of more mesoporous enlarges the specific surface area, causing abundant reaction sites on the surface of the catalyst, which enhances the adsorption and activation of dinitrogen molecules. The existence of oxygen vacancy reduces the band gap and enhances the absorption of visible light. Furthermore, the p-n heterostructure promotes the effective transfer and separation of photogenerated carriers. Compared with the original Cu2O or ZnO, the photocatalytic ammonia yield of Mo–Fe co-doped ZnO/Cu2O is increased by 6.6 and 7.3 times, respectively, reaching 119.42 μmol cm−2h−1.