New method and mechanism for state-of-the-art gas purification
Researchers from Tokyo Metropolitan University have developed a way to mount gold nanoparticles on a molecular support known as a polyoxometalate (POM). They successfully applied this to realize nearly 100% conversion of carbon monoxide (CO) over a wide temperature range, demonstrating stable performance over long periods of time.
New catalyst consisting of gold nanoparticles supported on a Keggin-type polyoxometalate (POM) with a cesium salt. The structure showed high activity and stability for CO oxidation; trace amounts of water were found to be essential to the function of the material. Catalytic activity showed a unique, U-shaped dependence on temperature.
Credit: Toru Murayama
They showed how traces of water uniquely contribute to the catalyst's function, promising insight into catalysis and potential application to exhaust gas and room air purification.
Gas purification is an extremely important industrial process, whether in factories, catalytic converters for vehicle exhausts, or the domestic air purifier. Recently, research has focused on using nanometer-sized gold particles, prized for their ability to speed up ("catalyze") chemical reactions, even at very small (<5 nm) sizes. These often need to be mounted on a solid "support".
The research group of Toru Murayama (Project Professor) and Masatake Haruta (Professor) have successfully combined gold nanoparticles with polyoxometalates (POMs), a promising support material which has already attracted considerable attention in catalysis, medicine, surface and material sciences.
POMs and their salts, molecular ion species of metallic oxides, are yet to see widespread use for the stabilization of gold particles. By mounting gold particles down to a size of 2 nm using a sol immobilization method, they successfully applied it to a low-temperature carbon monoxide (CO) gas purifier.
Their new gold-POM catalyst not only showed efficient conversion at -50°C, top class performance even for a gold nanoparticle catalyst, but also demonstrated stable, 100% removal of a 1%vol concentration of CO over a span of 35 days at 0°C, with no degradation of the material.
They found that smaller particle sizes led to better performance, and that the conversion efficiency of the material showed a unique dependence on temperature. This led to the discovery that trace amounts of water were essential to the function of the material, the first unique mechanism proposed for catalysis in gold/POM catalysts.
The technique and newly discovered mechanism not only promise a greater understanding of catalysis, but also potential application to industrial filtration, both for gases and liquids.
This study was supported by the "Nanotechnology Platform" Program of the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan. The manuscript reporting this finding has been published online in Angewandte Chemie, International Edition.
Go Totsukawa | EurekAlert!
'Mushrooms' and 'brushes' help cancer-fighting nanoparticles survive in the body
23.10.2018 | Drexel University
Heredity matters: Ancestral protease functions as protein import motor in chloroplasts
23.10.2018 | Osaka University
A new building material developed at Empa is about to be launched on the market: "memory-steel" can not only be used to reinforce new, but also existing concrete structures. When the material is heated (one-time), prestressing occurs automatically. The Empa spin-off re-fer AG is now presenting the material with shape memory in a series of lectures.
So far, the steel reinforcements in concrete structures are mostly prestressed hydraulically. This re-quires ducts for guiding the tension cables, anchors for...
Scientists at the Max Planck Institute for Polymer Research (MPI-P) in Mainz (Germany) together with scientists from Dresden, Leipzig, Sofia (Bulgaria) and Madrid (Spain) have now developed and characterized a novel, metal-organic material which displays electrical properties mimicking those of highly crystalline silicon. The material which can easily be fabricated at room temperature could serve as a replacement for expensive conventional inorganic materials used in optoelectronics.
Silicon, a so called semiconductor, is currently widely employed for the development of components such as solar cells, LEDs or computer chips. High purity...
Augsburg chemists present a new technology for compressing, storing and transporting highly volatile gases in porous frameworks/New prospects for gas-powered vehicles
Storage of highly volatile gases has always been a major technological challenge, not least for use in the automotive sector, for, for example, methane or...
When we put water in a freezer, water molecules crystallize and form ice. This change from one phase of matter to another is called a phase transition. While this transition, and countless others that occur in nature, typically takes place at the same fixed conditions, such as the freezing point, one can ask how it can be influenced in a controlled way.
We are all familiar with such control of the freezing transition, as it is an essential ingredient in the art of making a sorbet or a slushy. To make a cold...
Thin organic layers provide machines and equipment with new functions. They enable, for example, tiny energy recuperators. In future, these will be installed...
23.10.2018 | Event News
17.10.2018 | Event News
16.10.2018 | Event News
23.10.2018 | Physics and Astronomy
23.10.2018 | Information Technology
23.10.2018 | Life Sciences