Promotional Effect of Cu for Catalytic Amination of Diethylene Glycol with Tertiarybutylamine over Ni–Cu/Al2O3 Catalysts

Polylactic acid-based plastic activated NiAl2O4 nanoparticles as highly active positive electrode materials for energy storage supercapacitor

A simple, low-cost, and environmentally benign process for synthesizing nanostructured NiO/NiAl2O4 on multiple kinds of carbon nanostructures (CNS) is presented. This method develops polylactic acid (PLA) based waste plastic materials for the producing CNS. These composites (NiO@NiAl2O4/CNS) were examined as potential electrodes in supercapacitors (SC) as they exhibit good charge/discharge reversibility and provide adequate specific capacitance values with a maximum being 1984 F/g at 0.5 A g-1. It is noteworthy that the cycling stability of this sample at 10 A g-1 maintained 101.7% of its initial capacity even after 5000 GCD cycles. An asymmetric supercapacitor (ASC) was built and analyzed, with NiO@NiAl2O4/CNS serving as the cathode and activated carbon serving as the anode of the device. The concluded device has an energy density of 58 Wh kg-1 with a power density of 986 W kg-1 and a SCs of 216.5 F/g. The results showed that the materials mentioned are a great option to use as electrode materials in applications involving the storage of energy.

Hydrogen Production by Ethanol Reforming on Supported Ni-Cu Catalysts

Supported bimetallic Ni-Cu catalysts with different Ni-Cu loadings on alumina (Al₂O₃), alumina-silica (Al₂O₃-SiO₂), alumina-magnesia (Al₂O₃-MgO), alumina-zinc oxide (Al₂O₃-ZnO), and alumina-lanthanum oxide (Al₂O₃-La₂O₃) were prepared and tested in ethanol steam reforming for the production of hydrogen (H₂). These catalysts were characterized by X-ray diffraction, H₂-temperature-programmed reduction, ammonia-temperature-programmed desorption, X-ray photoelectron spectroscopy, thermogravimetry, and differential scanning calorimetry. Cu addition improved the reducibility of NiO. Among the as-prepared catalysts, 30Ni5Cu/Al₂O₃-MgO and 30Ni5Cu/Al₂O₃-ZnO demonstrated much higher H₂ selectivity and excellent coke resistance compared to the other investigated catalysts. Over 30Ni5Cu/Al₂O₃-MgO and 30Ni5Cu/Al₂O₃-ZnO, the respective H₂ selectivity was 73.3 and 63.6% at 450 °C and increased to 94.0 and 95.2% at 600 °C. The strong interaction of Ni-Cu and Al₂O₃-ZnO (or Al₂O₃-MgO) led to the formation of smaller and highly dispersed CuO and NiO species on the carrier, which is conducive to improved catalytic performance. These Al₂O₃-MgO- and Al₂O₃-ZnO-supported bimetallic Ni-Cu materials can be promising catalysts for hydrogen production from ethanol steam reforming.

Structural Requirements for Chemoselective Ammonolysis of Ethylene Glycol to Ethanolamine over Supported Cobalt Catalysts

Ethylene glycol is regarded as a promising C2 platform molecule due to the fast development of its production from sustainable biomass. This study inquired the structural requirements of Co-based catalysts for the liquid-phase ammonolysis of ethylene glycol to value-added ethanolamine. We showed that the rate and selectivity of ethylene glycol ammonolysis on γ-Al2O3-supported Co catalysts were strongly affected by the metal particle size within the range of 2–10 nm, among which Co nanoparticles of ~4 nm exhibited both the highest ethanolamine selectivity and the highest ammonolysis rate based on the total Co content. Doping of a moderate amount of Ag further promoted the catalytic activity without affecting the selectivity. Combined kinetic and infrared spectroscopic assessments unveiled that the addition of Ag significantly destabilized the adsorbed NH3 on the Co surface, which would otherwise be strongly bound to the active sites and inhibit the rate-determining dehydrogenation step of ethylene glycol.