by Staff Writers
Tokyo, Japan (SPX) Aug 07, 2017
The principal component of petroleum and natural gas are hydrocarbons and their mixtures, and are indispensable as resources supporting modern infrastructure as raw materials for the petrochemical industry. A technique which has been conventionally used to create beneficial chemical products from hydrocarbons was to use a large amount of metallic peroxides in hazardous organic solvents to oxidize hydrocarbon compounds.
To use resources effectively and to reduce environmental impact, clean catalytic oxidization without solvents using the oxygen in the air has been a popular research subject in recent years. Research of noble metal nanoparticles supported on porous carbon materials or metallic oxides are especially prevalent, and they are viewed as promising catalysts.
Vital elements determining the reactivity of such heterogeneous catalysts are the shape, size, and metallic composition of the metallic nanoparticles.
Particles of a size less than 2 nm have especially gained attention in the development of new high-performance catalysts, since it has been found that reducing the diameter of the catalyst particle not only increases the surface area ratio but greatly changes the state of the electrons on the surface of the metals, greatly changing its reactivity.
However, the method of synthesizing metallic nanoparticles of such a size while controlling both its diameter and composition had not been discovered.
The research group led by Kimihisa Yamamoto of Tokyo institute of Technology developed a method of synthesizing microscopic alloy nanoparticles using branched molecules "dendrimers" they themselves had developed in Yamamoto Atom Hybrid Project on the ERATO program, the Exploratory Research for Advanced Technology, research funding program supported by Japan Science and Technology Agency (JST). Molecules called dendrimers have a regular branching structure with only one definite molecular weight although they are classified as macromolecules.
The research group implemented many coordination sites for forming metal ions and complexes. By using a dendrimer with such coordination sites as a template for the nanoparticle, the group was able to synthesize a nanoparticle with a controlled number of atoms.
Further, they evaluated the activity of this alloy nanoparticle as an oxidization catalyst for hydrocarbons under ordinary pressures when using oxygen in the air as the oxidizing agent, and found that its activity was 24 times greater than that of commercially available catalysts for oxidization of organic compounds.
They also found that, by adding a catalytic amount of organic hydroperoxide, this catalyst promotes the oxidization of hydrocarbon into aldehydes and ketones under ordinary temperatures and pressures.
Further, by comparing the changes in activity due to alloy catalysts of different metallic compositions and examining the composition and other characteristics of the intermediates, ketones and organic hydroperoxides, the group was able to observe the process of reaction promotion due to the alloying of the catalyst.
The knowledge gained from this research is anticipated to become a design guideline for new high-performance catalysts. The method for synthesizing alloy nanoparticles developed in this research can be used generally and applied to other metals.
For this reason, this could be said to be the technology uncovering the reactivity of other microscopic alloy nanoparticles, whose catalytic performance had not been known.
Further study is required on the increase of catalytic activity at the interface of copper and other noble metals in the oxidizing transformations of other organic compounds, not only the oxidization of hydrocarbons. Application is anticipated for next-generation high-performance materials in the fields as diverse as optics, electronics, and energy.
Blacksburg VA (SPX) Aug 07, 2017
By better understanding the behavior of water in its smallest form, a Virginia Tech professor and his undergraduate student could be improving the efficiency of removing condensation in a major way. Jonathan Boreyko, an assistant professor in the Department of Biomedical Engineering and Mechanics in the Virginia Tech College of Engineering, has been studying "jumping" dew droplets since he ... read more
Tokyo Institute of Technology
Space Technology News - Applications and Research
|The content herein, unless otherwise known to be public domain, are Copyright 1995-2017 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement|