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Herein, we show that gallium oxide can function as an efficient promoter for the Cu-catalysed hydrogenation of cinnamaldehyde. SBA-15-supported Cu–Ga$_{2}$O$_{3}$ nanoparticles with a constant Cu loading of 5 wt% and two Cu/Ga weight ratios of 5 and 2, respectively, were synthesised by incipient wetness impregnation followed by mild drying. Physico-chemical characterisation revealed that the metal dispersion, and thus the active surface area of copper, can be enhanced nine-fold upon the addition of gallium promoter, boosting the catalytic activity as compared with the unpromoted Cu/SBA-15 catalyst. Likewise, the presence of Ga$_{2}$O$_{3}$ improved the selectivity to cinnamyl alcohol.

In this work, a series of Ni‐WxC/carbon materials have been prepared from a MOF precursor, DUT‐8(Ni), following different tungsten deposition routes. After pyrolysis, nickel‐tungsten alloys and tungsten carbide phases over nitrogen‐doped carbons were obtained. These materials were applied to cellulose hydrogenolysis, where molar yields of up to 46 % in ethylene glycol (EG) and 9 % in propylene glycol (PG) were obtained at 245 °C after 1 hour of reaction time. The best performing catalyst demonstrated promising stability, as the EG yield remained constant over 3 recycling tests and very little nanoparticles sintering was observed. [ABSTRACT FROM AUTHOR]

The preparation of MOF composites is considered as an effective method to address the challenges of shaping MOFs and to create porous solids with enhanced properties and broader applications. In this study, CPO-27-Co was crystallized via a simple strategy within porous chitosan beads. The resulting CS@CPO-27-Co composites were tested for CO2 sorption and they demonstrated promising performances by exceeding 3 mmol(CO2) g−1. The versatility of this strategy was further demonstrated by replacing cobalt(II) ions with nickel(II), also leading to the isostructural CPO-27 framework. [ABSTRACT FROM AUTHOR]

Cellulose is an attractive nonedible feedstock for the production of chemicals, especially through metal catalysis. However, its hydrothermal catalytic conversion induces severe deactivation of catalysts, notably by metal leaching and structure sintering. In this work, we studied a series of nickel- and tungsten-based catalysts supported on porous carbon (C) or N-doped porous carbon (NC). These catalysts were formed from nanosized bimetallic particles of Ni and W supported on porous N-doped carbon supports. The supports were prepared by hydrothermal conversion of N-containing biopolymers, followed by pyrolysis under an inert atmosphere. The bimetallic nanoparticles were deposited by wet impregnation. The idea was to study the influence of N-doping of the support on the stability during the catalysis of the metal nanoparticles on the support. For instance, an amorphous nitrogen-doped carbon with a hierarchical porosity and a surface area up to 286 m²·g-1 was obtained from the hydrothermal pyrolysis of chitosan, and, depending on the activation atmosphere (H2 or N2), metal particles in the 15-30 nm size were obtained. Regarding the application to cellulose conversion, molar yields up to 20% in ethylene glycol and 8% in propylene glycol were obtained by a reaction at 245°C for 1 h using a nitrogen-activated catalyst. When the catalyst was activated under hydrogen, the ethylene glycol yield was increased to 51% while the propylene glycol yield remained low. Very interestingly, the presence of N-containing moieties within the carbon supports proved an interest by increasing the catalyst stability during successive reaction cycles. The ethylene glycol yield remained stable during 3 reaction cycles for the N-doped catalyst, as compared to the nondoped one, which presented an important deactivation after 3 cycles. [ABSTRACT FROM AUTHOR]

The rapid miniaturization of portable and wearable electronics has gained increasing demand for flexible and high-performance microscale energy storage devices such as micro-supercapacitors (MSCs) that provide flexibility and portability. Volumetric capacitance is the most significant metric for miniaturized capacitive energy storage units due to the limitations in device volume and active surface area. Herein, we have used an ultrathin (3.5 nm) two-dimensional (2D) Co(OH)2 nanosheet (NS) as an electrode material to fabricate a flexible, solid-state MSC on micropatterned laser-scribed graphene (LSG). On account of the combination of ultrathin morphology, in-plane geometry of interdigitated microelectrodes, and highly conductive and robust interaction of ultrathin Co(OH)2 NS and LSG, the Co(OH)2 NS-LSG-based micro-supercapacitor (CN-LSG MSC) exhibits high rate-capability and delivers a superior volumetric capacitance of 258 F cm−3 at 13 A cm−3 current density. Moreover, the CN-LSG MSC device achieved an excellent energy density of 22 mW h cm−3 at a power density of 6.8 W cm−3 with a remarkable cyclic stability of 96.4% even after 20 000 charge–discharge cycles. The fabricated CN-LSG MSC exhibits unaffected mechanical flexibility under different bending deformations. Additionally, we have demonstrated the possibility of integrating a CN-LSG MSC by connecting it in series and parallel configurations, which amplifies the operating voltage and output current, respectively. Therefore, the present research work opens a new avenue for the simple and scalable manufacture of ultrathin film-based MSCs promising for various lightweight, miniaturized, flexible, and wearable electronics. [ABSTRACT FROM AUTHOR]

Nitrogen‐containing molecules are used for the synthesis of polymers, surfactants, agrochemicals, and dyes. In the context of green chemistry, it is important to form such compounds from bioresource. Short‐chain primary amines are of interest for the polymer industry, like 2‐aminopropanol, 1‐aminopropan‐2‐ol, and 1,2‐diaminopropane. These amines can be formed through the amination of oxygenated substrates, preferably in aqueous phase. This is possible with heterogeneous catalysts, however, effective systems that allow reactions under mild conditions are lacking. We report an efficient catalyst Ru−Ni/AC for the reductive amination of hydroxyacetone into 2‐aminopropanol. The catalyst has been reused during 3 cycles demonstrating a good stability. As a prospective study, extension to the reactivity of (poly)carbohydrates has been realized. Despite a lesser efficiency, 2‐aminopropanol (9 % yield of amines) has been formed from fructose, the first example from a carbohydrate. This was possible using a 7.5 %Ru‐36 %WxC/AC catalyst, composition allowing a one‐pot retro‐aldol cleavage into hydroxyacetone and reductive amination. The transformation of cellulose through sequential reactions with a combination of 30 %W2C/AC and 7.5 %Ru‐36 %WxC/AC system gave 2 % of 2‐aminopropanol, corresponding to the first example of the formation of this amine from cellulose with heterogeneous catalysts. [ABSTRACT FROM AUTHOR]

Borophene is an emerging two-dimensional material exhibiting exceptional piezocatalytic activity under the influence of ultrasonic vibrations, as exemplified herein by the decomposition of highly stable organic dyes in water. After 6 minutes of exposure, borophene sheets converted up to 92 percent of a mixture of dye molecules at room temperature. [ABSTRACT FROM AUTHOR]