Electrochemical Catalytic Synthesis of CH3OH for In‐situ Resource Utilization

Posted on by
Electrochemical Catalytic Synthesis of CH3OH for In-situ Resource Utilization

The supply of resources is an important factor in realizing a sustainable development of outer space exploration. In-situ resource utilization (ISRU) can convert CO2 into O2, allowing resource recycling and reducing material supply requirements. An electrochemical catalytic synthesis of a CH3OH device for ISRU was designed to perform the generation of O2 and the reduction of CO2 at room temperature.


Abstract

In space exploration activities, a large amount of materials needs to be carried, which limits the sustainable development of exploration activities. In-situ resource utilization (ISRU) is an important means to realize resource recycling and continuous space exploration, which converts space resources into oxygen and hydrocarbon fuels. The traditional ISRU in outer space mainly uses high temperature and high pressure to electrolyze water or reduce CO2, having problems such as low conversion efficiency, high energy consumption, and excessive equipment volume. Here, an electrochemical catalytic synthesis technology based on a microfluidic device is proposed, which can convert H2O and CO2 into O2 and organic matter by electrocatalytic method at room temperature and achieve efficient energy and matter conversion. The gas-liquid mixing and electrochemical reaction were analyzed. A mathematical model of gas-liquid two-phase mixing and microfluidic chemical reaction was established. The research results demonstrate the reliability and efficiency of the microfluidic reaction device designed in this paper for ISRU.

Improved Reversible Capacity and Cycling Stability by Linear (N=O) Anions in Fe[Fe(CN)5NO] as Sodium‐Ion Battery Cathode

Posted on by
Improved Reversible Capacity and Cycling Stability by Linear (N=O) Anions in Fe[Fe(CN)5NO] as Sodium-Ion Battery Cathode

Innovative Fe[Fe(CN)5NO] (PBN) cathode material effectively eliminates the negative effects of crystal water in Prussian blue analogues (PBA) for sodium-ion batteries. PBN demonstrates lower crystal water content and volume expansion compared to traditional PBA. The N=O bond in PBN also enhances the diffusion potential of Na+ ions, leading to improved reversible capacity and cycling stability.


Abstract

Prussian blue analogues (PBAs) are promising cathode materials for sodium-ion batteries (SIBs) due to their tunable chemistry, open channel structure, and low cost. However, excessive crystal water and volume expansion can negatively impact the lifetime of actual SIBs. In this study, a novel iron nitroprusside: Fe[Fe(CN)5NO] (PBN) was synthesized to effectively eliminate the detrimental effects of crystal water on the reversible capacity and cycling stability of PBA materials. Experiments and DFT calculations demonstrated that PBN has lower crystal water and volume expansion compared to Fe[Fe(CN)6] (PB). Also, the N=O bond in PBN significantly reduces the diffusion potential of Na+ in the skeleton. Without any modification, the cathode material exhibited a capacity of up to 148.6 mAh g−1 at 50 mA g−1 as well as maintained 102.9 mAh g−1 after 200 cycles. This work expands our knowledge of the crystal structure of PBA cathode materials and facilitates the rational design of high-quality PBA cathodes for SIBs.

Remarkable Enhancement of Hole Mobility of Novel DA‐D’‐AD Small Molecules by Thermal Annealing: Effect of the D’‐Bridge Block.

Posted on by
Remarkable Enhancement of Hole Mobility of Novel DA-D’-AD Small Molecules by Thermal Annealing: Effect of the D’-Bridge Block.

Four novel conjugated small molecules (SM) are designed as organic semiconductor materials. Thermal treatment is shown as a powerful approach to control the morphology of SM-based thin films. Remarkable enhancement of hole mobilities of ca. 50 times is achieved for films based on compounds with triisiopropylsilyl-functionalized benzodithiophene cores.


Abstract

Conjugated small molecules are advanced semiconductor materials with attractive physicochemical and optoelectronic properties enabling the development of next-generation electronic devices. The charge carrier mobility of small molecules strongly influences the efficiency of organic and hybrid electronics based on them. Herein, we report the synthesis of four novel small molecules and their investigation with regard to the impact of molecular structure and thermal treatment of films on charge carriers’ mobility. The benzodithiophene-containing compounds (BDT) were shown to be more promising in terms of tuning the morphology upon thermal treatment. Impressive enhancement of hole mobilities by more than 50 times was found for annealed films based on a compound M4 comprising triisopropylsilyl-functionalized BDT core. The results provide a favorable experience and strategy for the rational design of state-of-the-art organic semiconductor materials (OSMs) and for improving their charge-transport characteristics.

Towards Higher NH3 Faradaic Efficiency: Selective‐Poisoning of HER Active Sites by Co‐Feeding CO in NO Electroreduction

Posted on by
Towards Higher NH3 Faradaic Efficiency: Selective-Poisoning of HER Active Sites by Co-Feeding CO in NO Electroreduction**

Poisoning to promote? Poisoning of cathode catalyst surface by CO induces suppression of hydrogen evolution reaction (HER) and drastically boosts the Faradaic efficiency of NO reduction to NH3 in a polymer electrolyte membrane (PEM) cell. The promotional effects towards selective ammonia formation is dependent on the type of metals which uniquely interact with CO with specific surface sites driving HER and/or NO reduction.


Abstract

Direct electroreduction of nitric oxide offers a promising avenue to produce valuable chemicals, such as ammonia, which is an essential chemical to produce fertilizers. Direct ammonia synthesis from NO in a polymer electrolyte membrane (PEM) electrolyzer is advantageous for its continuous operation and excellent mass transport characteristics. However, at a high current density, the faradaic efficiency of NO electroreduction reaction is limited by the competing hydrogen evolution reaction (HER). Herein, we report a CO-mediated selective poisoning strategy to enhance the faradaic efficiency (FE) towards ammonia by suppressing the HER. In the presence of only NO at the cathode, Pt/C and Pd/C catalysts showed a lower FE towards NH3 than to H2 due to the dominating HER. Cu/C catalyst showed a 78 % FE towards NH3 at 2.0 V due to the stronger binding affinity to NO* compared to H*. By co-feeding CO, the FE of Cu/C catalyst towards NH3 was improved by 12 %. More strikingly, for Pd/C, the FE towards NH3 was enhanced by 95 % with CO co-feeding, by effectively suppressing HER. This is attributed to the change of the favorable surface coverage resulting from the selective and competitive binding of CO* to H* binding sites, thereby improving NH3 selectivity.

Iron‐Catalyzed Amide Bond Formation from Carboxylic Acids and Isocyanates

Posted on by
Iron-Catalyzed Amide Bond Formation from Carboxylic Acids and Isocyanates †

We describe an iron-catalyzed amide bond formation from readily available carboxylic acids and isocyanates. This method utilizes an abundant and biocompatible iron catalyst and easily accessible starting materials, generates CO2 as the only byproduct, and features broad substrate scopes with good functional group compatibility.


Comprehensive Summary

We describe an iron-catalyzed amide bond formation from readily available carboxylic acids and isocyanates. This method utilizes an abundant and biocompatible iron catalyst and easily accessible starting materials, generates CO2 as the only byproduct, and features broad substrate scopes with good functional group compatibility. Therefore, it provides a cost-effective and practical protocol to access a diverse variety of amides.

The design of support effect in the catalytic application of ligand‐protect gold clusters

Posted on by

Ligand-protected gold (Aun) clusters sometimes need the removal of organic ligands to expose more active sites and reduce steric hindrance in catalytic reactions, and large amount of organic and inorganic materials usually need to be employed as supports to anchor Aun clusters through different interaction mechanisms. Whereas, less comprehensive summaries have been provided about the crucial contribution of various supports on the catalytic performance of the supported Aun clusters. Herein, this review firstly summarizes synthesis methods (e.g., impregnation and encapsulation processes) for the supported Aun cluster catalysts, and then mainly points out specific contributions of support effect in a great diversity of catalytic reactions, as well as deep interaction mechanisms. Besides, opportunities and challenging issues will be stated towards supported Aun clusters, in terms of improving catalytic performance and structural stability of Aun clusters in the demand of catalysis.

This article is protected by copyright. All rights reserved.

Mussel‐Inspired Adhesive Hydrogels: Chemistry and Biomedical Applications

Posted on by

Abstract

Adhesive hydrogels are an emerging class of hydrogels that combine three-dimensional hydrated networks with adhesive properties. These properties facilitate intimate tissue-material contact in diverse biomedical applications, enhancing tissue joining, drug transport, and signal transmission. Inspired by the universal adhesiveness of mussel foot proteins, 3,4-dihydroxyphenyl-L-alanine (DOPA) and its analogs have been extensively exploited for the fabrication of adhesive hydrogels, within which the DOPA moieties can not only serve as cross-linking mediators but also participate in various intermolecular and surface interactions to mediate wet adhesion. This mini-review highlights recent achievements in the development of mussel-inspired adhesive hydrogels, focusing on: (1) elucidating DOPA-mediated adhesion mechanisms through nanomechanical characterizations, (2) designing injectable adhesive hydrogels toward applications in drug delivery, hemostasis, and wound closure, which includes in situ gelling liquids and shear-thinning preformed hydrogels, and (3) fabricating tough adhesive hydrogels with enhanced mechanical properties for use in tissue regeneration, biosensing, and bioimaging, with typical examples of nanocomposite and double-network hydrogels. The challenges and prospects in this rapidly developing field are also discussed.

This article is protected by copyright. All rights reserved.

An Ultrahigh‐capacity Dual‐ion Battery Based on the Free‐standing Graphite paper cathode and Flower‐like Heterojunction Anode of Tin Disulfide and Molybdenum Disulfide

Posted on by

Dual-ion batteries have been considered as a competitive energy storage device. However, owing to the lack of the suitable high-capacity density and rapid-charging kinetics electrode materials, designing a cost-effective and high performance dual-ion battery is still a great challenge. Herein, an ultrahigh-capacity dual-ion battery is constructed based on the SnS2-MoS2@CNTs heterojunction anode and high crystallinity free-standing graphite paper serves as cathode. The SnS2-MoS2@CNTs heterojunction consisted of ultrathin nanosheets is prepared via a facile two-step hydrothermal method, and shows flower-like morphology and high crystallinity. Benefiting from the unique design concept, the Graphite paper/SnS2-MoS2@CNTs dual-ion battery delivers a high capacity of 274.2 mA h g-1 at 100 mA g-1 and keeps an outstanding capacity retention of 95% after 300 cycles under 400 mA g-1. Even at a high current density of 2 A g-1, the battery still retains a considerable capacity of 112.3 mA h g-1. More importantly, the battery shows an extremely low self-discharge of 0.006% h-1 after resting for 24 h. The characterization of SEM and XRD further demonstrate the excellent cycling stability and good reversibility. Consequently, this constructed dual-ion battery could be a promising energy storage device and provide new insight for the design of high-performance dual-ion batteries.