Self‐healing triboelectric nanogenerators (TENGs) with flexibility, robustness, and conformability are highly desirable for promising flexible and wearable devices, which can serve as a durable, ...stable, and renewable power supply, as well as a self‐powered sensor. Herein, an entirely self‐healing, flexible, and tailorable TENG is designed as a wearable sensor to monitor human motion, with infrared radiation from skin to promote self‐healing after being broken based on thermal effect of infrared radiation. Human skin is a natural infrared radiation emitter, providing favorable conditions for the device to function efficiently. The reversible imine bonds and quadruple hydrogen bonding (UPy) moieties are introduced into polymer networks to construct self‐healable electrification layer. UPy‐functionalized multiwalled carbon nanotubes are further incorporated into healable polymer to obtain conductive nanocomposite. Driven by the dynamic bonds, the designed and synthesized materials show excellent intrinsic self‐healing and shape‐tailorable features. Moreover, there is a robust interface bonding in the TENG devices due to the similar healable networks between electrification layer and electrode. The output electric performances of the self‐healable TENG devices can almost restore their original state when the damage of the devices occurs. This work presents a novel strategy for flexible devices, contributing to future sustainable energy and wearable electronics.
An entirely self‐healing, flexible and tailorable triboelectric nanogenerator as a self‐powered sensor to monitor human motion is designed. Human skin serving as a natural infrared emitter could provide favorable conditions for the device to realize real‐time self‐healing, based on the thermal effect of infrared radiation. The proposed strategy is general, contributing to future sustainable energy and wearable devices.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
The unique applications of porous metal–organic framework (MOF) liquids with permanent porosity and fluidity have attracted significant attention. However, fabrication of porous MOF liquids remains ...challenging because of the easy intermolecular self‐filling of the cavity or the rapid settlement of porous hosts in hindered solvents that cannot enter their pores. Herein, we report a facile strategy for the fabrication of a MOF liquid (Im‐UiO‐PL) by surface ionization of an imidazolium‐functionalized framework with a sterically hindered poly(ethylene glycol) sulfonate (PEGS) canopy. The Im‐UiO‐PL obtained in this way has a CO2 adsorption approximately 14 times larger than that of pure PEGS. Distinct from a porous MOF solid counterpart, the stored CO2 in Im‐UiO‐PL can be slowly released and efficiently utilized to synthesize cyclic carbonates in the atmosphere. This is the first example of the use of a porous MOF liquid as a CO2 storage material for catalysis. It offers a new method for the fabrication of unique porous liquid MOFs with functional behaviors in various fields of gas adsorption and catalysis.
An ionization strategy has been developed to fabricate a porous MOF liquid, which shows large adsorption of CO2. The adsorbed CO2 can subsequently be slowly released and efficiently utilized to synthesize, for example, cyclic carbonates.
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Metal-organic frameworks (MOFs) are porous crystalline materials constructed from metal ions or clusters and multidentate organic ligands. Recently, the use of MOFs or MOF composites as catalysts for ...synergistic catalysis and tandem reactions has attracted increasing attention due to their tunable open metal centres, functional organic linkers, and active guest species in their pores. In this review, the applications of MOFs with multiple active sites in synergistic organic catalysis, photocatalysis and tandem reactions are discussed. These multifunctional MOFs can be categorized by the type of active centre as follows: (i) open metal centres and functional organic linkers in the MOF structure, (ii) active guest sites in the pores and active sites in the MOF structure, and (iii) bimetallic nanoparticles (NPs) on MOF supports. The types of synergistic catalysis and tandem reactions promoted by multifunctional MOFs and their proposed mechanisms are presented in detail. Here, catalytic MOFs with a single type of active site and MOFs that only serve as supports to enhance substrate adsorption are not discussed.
Various active sites incorporated into metal-organic frameworks (MOFs) are suitable for synergistic catalysis and tandem reactions.
•An overview of reinforcement learning with tutorials for industrial practitioners on implementing RL solutions into process control applications.•An introduction to different reinforcement learning ...algorithms.•Recent successes of RL applications with emphasis on process control applications.•A comparison with traditional optimal control methods.
In recent years, reinforcement learning (RL) has attracted significant attention from both industry and academia due to its success in solving some complex problems. This paper provides an overview of RL along with tutorials for practitioners who are interested in implementing RL solutions into process control applications. The paper starts by providing an introduction to different reinforcement learning algorithms. Then, recent successes of RL applications across different industries will be explored, with more emphasis on process control applications. A detailed RL implementation example will also be shown. Afterwards, RL will be compared with traditional optimal control methods, in terms of stability and computational complexity among other factors, and the current shortcomings of RL will be introduced. This paper is concluded with a summary of RL’s potential advantages and disadvantages.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Herein, an effective tandem catalysis strategy is developed to improve the selectivity of the CO2RR towards C2H4 by multiple distinct catalytic sites in local vicinity. An earth‐abundant ...elements‐based tandem electrocatalyst PTF(Ni)/Cu is constructed by uniformly dispersing Cu nanoparticles (NPs) on the porphyrinic triazine framework anchored with atomically isolated nickel–nitrogen sites (PTF(Ni)) for the enhanced CO2RR to produce C2H4. The Faradaic efficiency of C2H4 reaches 57.3 % at −1.1 V versus the reversible hydrogen electrode (RHE), which is about 6 times higher than the non‐tandem catalyst PTF/Cu, which produces CH4 as the major carbon product. The operando infrared spectroscopy and theoretic density functional theory (DFT) calculations reveal that the local high concentration of CO generated by PTF(Ni) sites can facilitate the C−C coupling to form C2H4 on the nearby Cu NP sites. The work offers an effective avenue to design electrocatalysts for the highly selective CO2RR to produce multicarbon products via a tandem route.
An effective tandem catalysis strategy is developed to enhance the selectivity of the CO2 electroreduction reaction towards C2H4 with a 6‐fold increase in comparison with that of the non‐tandem catalysts. The local high concentration of CO generated by atomically isolated nickel–nitrogen sites PTF(Ni) sites can facilitate the C−C coupling to form C2H4 on the nearby Cu NP sites, thus switching from CH4 to C2H4 production with a Faradaic efficiency of 57.3 %.
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It is still a great challenge to achieve high selectivity of CH4 in CO2 electroreduction reactions (CO2RR) because of the similar reduction potentials of possible products and the sluggish kinetics ...for CO2 activation. Stabilizing key reaction intermediates by single type of active sites supported on porous conductive material is crucial to achieve high selectivity for single product such as CH4. Here, Cu2O(111) quantum dots with an average size of 3.5 nm are in situ synthesized on a porous conductive copper‐based metal–organic framework (CuHHTP), exhibiting high selectivity of 73 % towards CH4 with partial current density of 10.8 mA cm−2 at −1.4 V vs. RHE (reversible hydrogen electrode) in CO2RR. Operando infrared spectroscopy and DFT calculations reveal that the key intermediates (such as *CH2O and *OCH3) involved in the pathway of CH4 formation are stabilized by the single active Cu2O(111) and hydrogen bonding, thus generating CH4 instead of CO.
Cu2O(111) single‐type sites on a conductive metal–organic framework are successfully prepared by an in situ electrochemical method. The cooperative effect between the single active Cu2O(111) and hydrogen bonding contributes to the high selectivity of 73 % towards CH4 with large current density in CO2 electroreduction reduction for the obtained Cu2O(111)@CuHHTP.
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The electrocatalytic conversion of CO2 into value‐added chemicals is a promising approach to realize a carbon‐energy balance. However, low current density still limits the application of the CO2 ...electroreduction reaction (CO2RR). Metal–organic frameworks (MOFs) are one class of promising alternatives for the CO2RR due to their periodically arranged isolated metal active sites. However, the poor conductivity of traditional MOFs usually results in a low current density in CO2RR. We have prepared conductive two‐dimensional (2D) phthalocyanine‐based MOF (NiPc‐NiO4) nanosheets linked by nickel‐catecholate, which can be employed as highly efficient electrocatalysts for the CO2RR to CO. The obtained NiPc‐NiO4 has a good conductivity and exhibited a very high selectivity of 98.4 % toward CO production and a large CO partial current density of 34.5 mA cm−2, outperforming the reported MOF catalysts. This work highlights the potential of conductive crystalline frameworks in electrocatalysis.
Nickel phthalocyanine molecules as active sites were installed into nickel‐catecholate‐linked 2D conductive metal–organic framework nanosheets for efficient CO2 electroreduction with nearly 100 % CO selectivity.
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The electroreduction of CO2 to value‐added chemicals such as CO is a promising approach to realize carbon‐neutral energy cycle, but still remains big challenge including low current density. Covalent ...organic frameworks (COFs) with abundant accessible active single‐sites can offer a bridge between homogeneous and heterogeneous electrocatalysis, but the low electrical conductivity limits their application for CO2 electroreduction reaction (CO2RR). Here, a 2D conductive Ni‐phthalocyanine‐based COF, named NiPc‐COF, is synthesized by condensation of 2,3,9,10,16,17,23,24‐octa‐aminophthalocyaninato Ni(II) and tert‐butylpyrene‐tetraone for highly efficient CO2RR. Due to its highly intrinsic conductivity and accessible active sites, the robust conductive 2D NiPc‐COF nanosheets exhibit very high CO selectivity (>93%) in a wide range of the applied potentials of −0.6 to −1.1 V versus the reversible hydrogen electrode (RHE) and large partial current density of 35 mA cm−2 at −1.1 V versus RHE in aqueous solution that surpasses all the conventional COF electrocatalysts. The robust NiPc‐COF that is bridged by covalent pyrazine linkage can maintain its CO2RR activity for 10 h. This work presents the implementation of the conductive COF nanosheets for CO2RR and provides a strategy to enhance energy conversion efficiency in electrocatalysis.
A conductive nickelophthalocyanine‐based 2D covalent organic framework is synthesized and employed as a robust and efficient electrocatalyst for CO2 electroreduction reaction, providing a new route to design highly efficient porous framework materials for the enhanced electrocatalysis via improving electrical conductivity.
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Multivariate statistical process monitoring involves dimension reduction and latent feature extraction in large-scale processes and typically incorporates all measured variables. However, involving ...variables without beneficial information may degrade monitoring performance. This study analyzes the effect of variable selection on principal component analysis (PCA) monitoring performance. Then, it proposes a fault-relevant variable selection and Bayesian inference-based distributed method for efficient fault detection and isolation. First, the optimal subset of variables is identified for each fault using an optimization algorithm. Second, a sub-PCA model is established in each subset. Finally, the monitoring results of all of the subsets are combined through Bayesian inference. The proposed method reduces redundancy and complexity, explores numerous local behaviors, and provides accurate description of faults, thus improving monitoring performance significantly. Case studies on a numerical example, the Tennessee Eastman benchmark process, and an industrial-scale plant demonstrate the efficiency.
Free N‐heterocyclic carbenes (NHCs) are generally prepared by treatment of imidazolium precursors with strong alkali reagents, which usually produces inactive NHC dimers. This treatment would destroy ...porous supports and thus make supported NHC catalysts difficult to recovery and reuse. Herein, we report the first stable CO2‐masked N‐heterocyclic carbenes (NHCs) grafted on a porous crystalline covalent organic framework (COF). The stable NHC‐CO2 moieties in the COF‐NHC‐CO2 could be transformed in situ into isolated NHCs by heating, which exhibit superior catalytic performances in hydrosilylation and N‐formylation reactions with CO2. The NHC sites can reversibly form NHC‐CO2 and thus can be easily recycled and reused while maintaining excellent catalytic activity. Density functional theory calculations revealed that NHC sites can be fully exposed after removal of CO2‐masks and rapidly react with silanes, which endows COF‐NHC with high catalytic activity.
A stable CO2‐masked N‐heterocyclic carbene (NHC) decorated covalent organic framework (COF‐NHC‐CO2) heterogeneous catalyst is prepared. COF‐NHC‐CO2 catalyzes the hydrosilylation of CO2 and the N‐formylation of amines with CO2 to produce methanol and formamides. The activities rank COF‐NHC‐CO2 among the most active heterogeneous catalysts for these CO2 fixation reactions.
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