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We report a smart ion-exchange strategy to anchor molybdenum oxide particles on charge-modulated conjugated triazine frameworks (Mo/CTF-I) for electrochemically fixing nitrogen. The strong interaction between MoOx and CTF-I is conducive to the activation of the inert N2 molecule in the electro-chemical process. As a result, 5% Mo/CTF-I exhibited an excellent faradaic efficiency of 27.3% and an NH3 yield rate of 7.23 μg h−1 mgcat.−1 at −0.405 V vs. RHE in 0.1 M KOH, surpassing most previous reports. [ABSTRACT FROM AUTHOR]

To resolve the issues of a highly polluting and energy-intensive industry based on the Reppe method, herein we developed an economically feasible green route for the synthesis of poly(tetramethylene ether glycol) (PTMEG) and methane from furfural (FA). The synthesis route consisted of the base metal Ni and/or Cu catalyzed full hydrogenation of FA, followed by the subsequent selective hydrodeoxygenation of tetrahydrofurfuryl alcohol (THFA) to tetrahydrofuran (THF) and methane. The latter was the key step for the process, where tetrahydrofurfural acted as an important intermediate in the alcohol–aldehyde equilibrium of THFA conversion on the Ni surface in a fix-bed reactor. This was followed by its decarbonylation to 2,3-dihydrofuran and CO, and subsequent hydrogenation to THF and methane. THF polymerization was catalyzed by phosphotungstic acid (PWA) with epichlorohydrin (ECH) as the initiator to produce PTMEG with a controllable molecular weight and distribution (Mw = 1889, D = 1.483). The comparative techno-economic analysis also demonstrated that the furfural method was more responsive to economic and green concerns than the traditional Reppe technique. Therefore, as the highly polluting and energy-intensive Reppe industry will most likely be restricted in a low carbon society, the green and economical furfural method is poised to establish sustained competitiveness for producing bio-PTMEG and bio-methane in the future. [ABSTRACT FROM AUTHOR]

Chemical warfare agents, particularly nerve agents such as sarin, are exceptionally harmful and incredibly perilous to people. Thus, the sensitive detection of these gases is indispensable for reducing the risk of chemical weapons. Herein, we fabricated a room-temperature chemiresistive gas sensor based on two-dimensional few-layer tungsten diselenide (WSe2) nanosheets, which were prepared through a facile liquid-phase exfoliation method. The WSe2-based sensor has demonstrated sensitive and selective detection of dimethyl methylphosphonate (DMMP), which is a well-known simulant of the nerve agent sarin. The sensor based on WSe2 nanosheets revealed a high response reaching 8.91% to 10 ppm DMMP with a fast response time of 100 s. Furthermore, the sensor displayed reliable stability, excellent selectivity, and a low theoretical limit of detection of about 122 ppb. The enhanced sensing performance of WSe2 nanosheets can be ascribed to the increase of the specific surface area, which provides more active adsorption sites for DMMP molecules, thereby facilitating the charge transfer process between DMMP molecules and WSe2 nanosheets. Overall, our results indicate that two-dimensional transition metal dichalcogenide materials have the potential for the design and fabrication of high-performance nerve agent sensing devices. [ABSTRACT FROM AUTHOR]

Metal phthalocyanines (MPcs) have attracted great interest in the gas sensing field, but the long recovery time with hard desorption of gas has hindered their further practical application. The combination of cobalt and carboxyl groups increases the electron concentration. Herein, cobalt phthalocyanine (CoPc–COOH) modified with carboxyl groups was prepared and applied to detect nitrogen dioxide (NO2) and its sensing performance at room temperature was determined. These CoPc–COOH nanofibres have demonstrated outstanding recovery performance at an ultralow laser exposure. In particular, UV-Vis and FTIR results indicate no change in the molecular structure of CoPc–COOH powders before and after laser exposure. The enhancement in the recovery properties of the laser-assisted method can be attributed to the generation of electron and hole pairs in the CoPc–COOH nanofibres, where the adsorbed NO2 molecules transformed from NO2− to NO2 by taking one hole with faster desorption. Thus, our study provides a valuable gas sensing recovery mode and mechanism for constructing practical gas sensors. [ABSTRACT FROM AUTHOR]

The recalcitrance of lignin with non-hydrolyzable C–O–C bonds, as well as the tendency for its phenolic fragments to polymerize into more recalcitrant polymers, leads to low-efficiency lignin deconstruction processes, such as low lignin concentrations during treatment. Herein, we developed a tandem catalytic approach for the conversion of highly concentrated lignin to stable cyclic alkanes by introducing Pt/HAP into a Ni/ASA catalyst in dodecane media. The incorporated Pt/HAP changes the simultaneous hydrogenation and hydrogenolysis of lignin on Ni/ASA into tandem reactions on a physically mixed Pt/HAP and Ni/ASA catalyst, involving the initial selective lignin depolymerization over Pt/HAP and the following hydrodeoxygenation of phenols over Ni/ASA, as evidenced by kinetic studies. In this tandem approach, the preferred initial lignin depolymerization, instead of lignin hydrogenation, originates from the strong adsorption and high C–O cleavage selectivity of lignin on the introduced Pt/HAP, as confirmed by UV-Vis, gel permeation chromatography (GPC), 2D-heteronuclear single quantum coherence nuclear magnetic resonance (2D-HSQC NMR), and catalytic tests. The rates of lignin depolymerization and the hydrodeoxygenation of depolymerized phenols are matched when the mass ratio of Pt/HAP and Ni/ASA is set at 1 : 1, allowing this approach to proceed with the highest lignin concentrations (150 g L−1) so far reported, with conversion to cyclic alkanes with 42 wt% yield without coke formation in dodecane at 300 °C in the presence of 6 MPa H2. Promisingly, the developed approach may lay a solid foundation for future industrial applications relating to lignin valorization. [ABSTRACT FROM AUTHOR]

In this contribution, we report a facile and green process for the quantitative transformation of natural oils, fatty esters, and fatty acids to fatty alcohols over N-modified carbon (N–C) supported RuSn catalysts in water at low temperatures (140–180 °C). The synthesis of the N–C support was carried out by using a one-pot process with melamine, glucose, and ZnCl2 as reactants. The presence of Sn nanoparticles, and pyridinic and pyrrolic nitrogen in the modified N–C support favoured the good dispersion of Ru nanoparticles, improved the hydrophilic properties of the catalyst for staying in the water layer, and facilitated the adsorption of the carbonyl groups. After strongly interacting with the carbonyl group of fatty acids over Sn nanoparticles and N-groups, Ru nanoparticles catalysed the further acid hydrogenation to the intermediate aldehyde, and subsequently to the target fatty alcohol at a fast rate. This provides a useful and simple method for synthesizing highly hydrothermal-stable metal supported carbon catalysts, which can facilely and selectively hydrogenate the aqueous biomass to value-added chemicals. [ABSTRACT FROM AUTHOR]

Hydrothermal reduction under aqueous conditions is widely used to convert biomass into more valuable products. However, the harsh conditions inherent in the process can irreversibly alter the intrinsic structure of the support, as well as dissolve the metal ions into the aqueous solution. In this work, for the first time we have synthesized a new highly hydrothermally stable Ru/LaCO3OH catalyst mostly consisting of Ru nanoparticles partially encapsulated by the LaCO3OH support with a strong metal–support interaction (SMSI), which confers high stability and activity to the catalyst under hydrothermal reduction conditions in the hydrogenolysis of the biomass model molecules guaiacol and glycerol. During impregnation, the RuCl3·3H2O precursor initially reacts with LaCO3OH to form a LaRu(CO3)2Cl2 complex and LaOCl. XPS demonstrated that Ru was present in the oxidized state, TEM and XRD showed the absence of Ru0, and the XRD pattern showed the presence of the characteristic lattice fringe of LaOCl. While the LaRu(CO3)2Cl2 complex was resistant to H2 reduction at 350 °C, the complex underwent facile reduction to Ru0 under hydrothermal conditions at 240 °C. In the subsequent process, LaRu(CO3)2Cl2 and LaOCl underwent hydrolysis, forming crystalline LaCO3OH (confirmed by Ag+ titration and XRD patterns), Ru(OH)3, and HCl. The Ru(OH)3 was reduced in situ to Ru0 nanoparticles, as revealed by XPS and TEM analysis. The simultaneous hydrothermal reduction of Run+ species and the formation of crystalline LaCO3OH result in the formation of Ru nanoparticles encapsulated by a protective LaCO3OH layer, as evidenced by HRTEM and DRIFTS CO adsorption measurements. The preparation of catalysts with this unique structure comprising metal nanoparticles protected by the support itself, which confers additional stability, is a novel strategy to prepare hydrothermally stable catalysts. [ABSTRACT FROM AUTHOR]

A novel one-pot approach selects a hydrothermally synthesized Cu/SiO2 catalyst (consisting of Cu2O·SiO2 and Cu0 surface species) to catalyze the reduction of a series of fatty esters, fatty acids, and coconut oil to fatty alcohols at 240 °C in methanol without extraneous hydrogen, attaining around 85% conversion and 100% selectivity. [ABSTRACT FROM AUTHOR]

Correction for 'The conversion of a high concentration of lignin to cyclic alkanes by introducing Pt/HAP into a Ni/ASA catalyst' by Shufang Qin et al., Green Chem., 2020, 22, 2901–2908, DOI: 10.1039/D0GC00243G. [ABSTRACT FROM AUTHOR]

Metal phthalocyanine (MPc) has a great saturation response value, but its low conductivity and slow response speed limit its practical application. A novel hybrid material composed of graphene quantum dots (GQDs) and metal phthalocyanine derivatives has been obtained. GQDs can be anchored onto the surface of MPc nanofibers through π-π stacking. The response to NO 2 can be significantly enhanced under certain component proportion matching, which is much better than their respective response to NO 2 . The introduction of GQDs greatly increases the conductivity of phthalocyanine fibers, leading to a faster response of the hybrid material. In addition, the reproducibility, selectivity and stability of the hybrid materials are excellent, and the minimum response concentration can reach 50 ppb. Ultra-low-power laser irradiation was used to solve the problem of slow recovery of metal phthalocyanine. Overall, we present the advantages of combining MPc nanofibers with GQDs and pave a new avenue for the application of MPc-GQD hybrids in the gas sensing field., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Chemical warfare agents, particularly nerve agents such as sarin, are exceptionally harmful and incredibly perilous to people. Thus, the sensitive detection of these gases is indispensable for reducing the risk of chemical weapons. Herein, we fabricated a room-temperature chemiresistive gas sensor based on two-dimensional few-layer tungsten diselenide (WSe2) nanosheets, which were prepared through a facile liquid-phase exfoliation method. The WSe2-based sensor has demonstrated sensitive and selective detection of dimethyl methylphosphonate (DMMP), which is a well-known simulant of the nerve agent sarin. The sensor based on WSe2 nanosheets revealed a high response reaching 8.91% to 10 ppm DMMP with a fast response time of 100 s. Furthermore, the sensor displayed reliable stability, excellent selectivity, and a low theoretical limit of detection of about 122 ppb. The enhanced sensing performance of WSe2 nanosheets can be ascribed to the increase of the specific surface area, which provides more active adsorption sites for DMMP molecules, thereby facilitating the charge transfer process between DMMP molecules and WSe2 nanosheets. Overall, our results indicate that two-dimensional transition metal dichalcogenide materials have the potential for the design and fabrication of high-performance nerve agent sensing devices.

Metal phthalocyanines (MPcs) have attracted great interest in the gas sensing field, but the long recovery time with hard desorption of gas has hindered their further practical application. The combination of cobalt and carboxyl groups increases the electron concentration. Herein, cobalt phthalocyanine (CoPc-COOH) modified with carboxyl groups was prepared and applied to detect nitrogen dioxide (NO 2 ) and its sensing performance at room temperature was determined. These CoPc-COOH nanofibres have demonstrated outstanding recovery performance at an ultralow laser exposure. In particular, UV-Vis and FTIR results indicate no change in the molecular structure of CoPc-COOH powders before and after laser exposure. The enhancement in the recovery properties of the laser-assisted method can be attributed to the generation of electron and hole pairs in the CoPc-COOH nanofibres, where the adsorbed NO 2 molecules transformed from NO 2 - to NO 2 by taking one hole with faster desorption. Thus, our study provides a valuable gas sensing recovery mode and mechanism for constructing practical gas sensors.

A novel one-pot approach selects a hydrothermally synthesized Cu/SiO 2 catalyst (consisting of Cu 2 O·SiO 2 and Cu 0 surface species) to catalyze the reduction of a series of fatty esters, fatty acids, and coconut oil to fatty alcohols at 240 °C in methanol without extraneous hydrogen, attaining around 85% conversion and 100% selectivity.