 |
Recently, Professor Ma Mingming's group at the University of Science and Technology of China has designed a hollow nanosphere formed by the self-assembly of cobalt nanocrystals. It can be used as a catalyst to efficiently catalyze the production of hydrogen in electrolyzed water in neutral aqueous solutions and can be used at high current densities. Long time stable work. The research results were published online on Angew. Chem. Int. Ed. (doi:10.1002/anie.201601367) and were selected as the inside cover. The first author of the thesis was Liu Bingrui, a doctoral student of the research group.
Currently, industrially used electrohydrogen production catalysts for electrolysis use precious metals such as platinum, which are expensive and resource-poor. The use of non-precious metal materials for the preparation of hydrogen electrocatalysts for electrolysis of water has become a research hotspot. However, most of the hydrogen catalysts for electrolytic electrolysis currently need to be used in strong acids or strong alkaline electrolytes, which may bring about some environmental and safety problems. For this reason, the development of high-performance hydrogen-producing electrocatalysts that can work in neutral electrolytes has important application value.
Ma Mingming's group prepared a nano-hollow sphere (Co-HNP) with a diameter of 5-10 nm by self-assembly of cobalt nanocrystals, using a "sacrificial template method", with a layer containing cobalt, tungsten and phosphorus. The composite oxide with boron binds the cobalt nanocrystals together to form a spherical shell and protects the cobalt nanocrystals from oxidation. This nano hollow ball is closely adsorbed on the conductive carbon cloth to form an electrode, which can not only ensure the effective electron transfer between the cobalt nanocrystals and between the cobalt nanocrystals and the carbon cloth, but also maintain the high specific surface area and size of the nanocatalyst. Effect, thus achieving a high catalytic activity of the electrode. On the other hand, due to the presence of the composite oxide protective layer, the catalyst can produce hydrogen in a neutral aqueous solution at a high current density of 150 mA cm-2 for 20 hours without significant inactivation. Under the same conditions, commercial platinum/carbon catalysts have been severely deactivated after 3 hours of hydrogen production. It can be seen that the nano-hollow spherical catalysts based on cobalt nanocrystals have both high activity and high stability in neutral aqueous solutions and are superior to noble metal platinum/carbon catalysts.
This work is of great significance for the design and development of high-performance electrochemical catalysts based on non-precious metal nanocrystals.
The study was funded by the National Natural Science Foundation of China and the Thousand Talents Program of the Central Organization Department.
Mitsubishi Elevator Spare Parts
Mitsubishi Elevator Spare Parts, Mitsubishi Elevator Parts
Shanghai Mitsubishi Elevator Spare Parts, Shanghai Mitsubishi Elevator Parts
|
|
|
|
|
A major name in elevators and escalators since the 1930s, Mitsubishi Electric has built a reputation for creating breakthroughs that make getting around more comfortable, safe, and even inspiring. Take our spiral escalator, for example. A Mitsubishi Electric original, it`s not only fun to ride, but has opened up entirely new possibilities in public space design. Its development required years of dedicated effort to overcome the immense physical, technical and mechanical challenges involved. Then there`s our super high-speed elevator, the culmination of decades of engineering experience and precision craftsmanship. It provides an ultra-fast, reliable riding experience with imperceptible vibration and noise. And there`s artificial intelligence technology that [learns" a building`s traffic patterns to deliver a more responsive service. Mitsubishi Electric is dedicated to creating better point-to-point transport experiences for all. We`re also a leading manufacturer of moving walks and home elevators. |
Mitsubishi Elevator Spare Parts,Mitsubishi Elevator Parts
CEP Elevator Products ( China ) Co., Ltd. , https://www.zjsmartcommercialescalators.com