Search

Metal‐based nanocatalysts supported on carbon have significant prospect for industry. However, a straightforward method for efficient and stable nanocatalysts still remains extremely challenging. Inspired by the structure and comptosition of cell walls and membranes, an ion chemical bond anchoring, an in situ carbonization coreduction process, is designed to obtain composite catalysts on N‐doped 2D carbon (C‐N) loaded with various noble and non‐noble metals (for example, Pt, Ru, Rh, Pd, Ag, Ir, Au, Co, and Ni) nanocatalysts. These 2 nm particles uniformly and stably bond with the C‐N support since the agglomeration and growth are suppressed by anchoring the metal ions on the cell wall and membrane during the carbonization and reduction reactions. The Pt@C‐N exhibits excellent catalytic activity and long‐term stability for the hydrogen evolution reaction, and the relative overpotential at 100 mA cm−2 is only 77 mV, which is much lower than that of commercial Pt/C and Pt single‐atom catalysts reported recently. [ABSTRACT FROM AUTHOR]

Abstract: This report describes a novel method to produce fluffy and resilient nanotube aerogels by combining solution blow spinning and Atom Layer Deposition (ALD). Polyvinylpyrrolidone (PVP) sponges obtained by blow spinning are used as templates and are deposited in ALD. After removal of template, semitransparent aerogels whose density can be as low as 0.68 mg/cm3 were obtained. The product is heat‐stable, with the ability to retain original shape and keep elastic after being kept at 900°C for 2 hours. It is also heat‐insulated, with a thermal conductivity of 0.022 W/K∙m at room temperature. Additionally, when compressed to 60% of the original height for 100 cycles during in‐situ mechanical test, the sponges recovered to around 80% of the original shape, further indicating excellent mechanically elasticity of the aerogel. [ABSTRACT FROM AUTHOR]

Aiming at the poor water-carrying capacity of foam in air drilling, this paper proposed a novel technology based on a solid phase water carrying agent. Studies were also carried out to analyze the carrying capacity, carrying rate, and adhesion properties of the solid phase water-carrying technology as well as the influence of the pressure on the adsorption capabilities of water. Furthermore, field test was conducted based on the main contents of the solid phase water-carrying technology studies. Results showed that when compared with the traditional foam, this technology has the characteristics of high water-carrying rate and capacity. It wouldn't affect the normal drilling and does not hold pressure, etc. This technology has important significance to reduce the drilling cost and improve the drilling speed. At the same time, it also verifies the reliability and feasibility of the technology. [ABSTRACT FROM AUTHOR]

Electromagnetic interference (EMI) is a type of pollution that is caused by the ubiquitous usage of electronic communication in general, and military radar equipment in particular. Even though this is a common problem for a long time, the fabrication of large‐area, flexible, and robust EMI shielding materials is still a challenge today. In this work, the 3D meshing strategy is simulated for most efficient utilization of metallic silver for X‐band EMI shielding, and propose a roll‐to‐roll (R2R) process to fabricate robust, flexible, and large‐scale EMI shielding sponge, silver nanowires/polyvinyl butyral (PVB) melamine sponge (AgPMS). Typically, 0.5 cm thick sponge has about 60 dB total EMI shielding efficiency (SE) in the microwave band, which is higher than for commercial EMI shielding sponges (about 45 dB) of the same thickness. AgPMS shows unchanged electrical properties after 1000 compression and bending cycles. Moreover, a AgPMS garment is made to demonstrate the excellent EMI shielding performance and remarkable flexibility of this material. Those properties suggest that AgPMS can be readily applied in challenging environments like hospitals, military installations, remote communication centers, and for any devices with curved surfaces. [ABSTRACT FROM AUTHOR]

Novel and stringent automotive exhaust gas emissions standards are urgently needed to counter the problems posed by the worsening global climate and environment. However, the traditional cordierite-based honeycomb ceramics substrates with ultimate pore density have seriously restricted the establishment of new emission standards. Herein, we introduce a novel robust substrate with tailored volume-specific surface area and low heat capacity. This substrate employs the synergy of high-strength ceramic fibers and ultrathin TiO 2 nanosheets. The micro-sized fibers provide support to ensure structural strength during the catalytic reaction, while the nanosheets play the dual role of connecting the fibers and providing a high surface area for catalyst immobilization. The new three-dimensional (3D) microarchitecture exhibits a high volume-specific surface area of 3.59×10 4  cm 2 /cm 3 , a compressive strength of 2.01 MPa, and remarkable stability after high-speed air erosion at 800 °C. The honeycomb-like structure exhibit low resistance to gas flow. Furthermore, after loading with Pt and Pd nanoparticles, the composite 3D microarchitecture delivered an excellent catalytic performance and prominent structural stability, with a super low light-off temperature of 150 °C. The outstanding mechanical and thermal stability and the high surface area and light-off temperature of the new substrate indicate its potential for use as a highly efficient catalytic carrier to meet the next-generation auto emissions standards., (© 2022 Wiley-VCH GmbH.)

Particulate matter (PM) is a major air pollutant in many regions, jeopardizing ecosystems and public health. Filtration at pollutant source is one of the most important ways to protect the environment, however, considering the high-temperature exhaust gas emissions, effective removal of PM and related pollutants from their sources remains a major challenge. In this study, a resilient, heat-resisting, and high-efficiency PM filter based on yttria-stabilized ZrO 2 (YSZ) nanofiber sponge produced with a scalable solution blow spinning process is reported. The porous 3D sponge composed of YSZ nanofibers is lightweight (density of 20 mg cm -3 ) and resilient at both room temperature and high temperatures. At room-temperature conditions, the YSZ nanofiber sponge exhibits 99.4% filtration efficiency for aerosol particles with size in the range of 20-600 nm, associated with a low pressure drop of only 57 Pa under an airflow velocity of 4.8 cm s -1 . At a high temperature of 750 °C, the ceramic sponge maintains a high filtration efficiency of 99.97% for PM 0.3-2.5 under a high airflow velocity of 10 cm s -1 . A practical vehicle exhaust filter to capture particles with filtration efficiency of >98.3% is also assembled. Hence, the YSZ nanofiber sponge has enormous potential to be applied in industry., (© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)