Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Catalyst Keeps Fruit Fresh Longer

13.05.2013
Ripening fruit, vegetables, and flowers release ethylene, which works as a plant hormone. Ethylene accelerates ripening, so other unripened fruit also begins to ripen—fruit and vegetables quickly spoil and flowers wilt.

In the journal Angewandte Chemie, Japanese researchers have now introduced a new catalytic system for the fast and complete degradation of ethylene. This system could keep the air in warehouses ethylene-free, keeping perishable products fresh longer.



Ethylene is not just a feedstock for the chemical industry; it also acts as a plant hormone, regulating many physiological processes, such as the ripening of fruits and the blooming and wilting of flowers. A familiar example of this is bananas left in a plastic bag, which ripen much faster than those left out. This type of acceleration of ripening even happens in a refrigerator at temperatures around 0 °C.

It is thus very important for wholesalers to remove traces of ethylene from warehouses and cold-storage facilities where fruit, vegetables, and flowers are stored. Previous biotechnological removal methods are expensive, complex, or ineffective. The search for a suitable catalyst for the oxidation of ethylene has also not been very successful. The stumbling block has been the low temperature at which the process must work.

Atsushi Fukuoka and his co-workers at Hokkaido University tested different metals in combination with a variety of support materials to develop an effective catalyst. They met with success: Platinum nanoparticles on a support made of special mesoporous silicon dioxide (MCM-41) demonstrated very high activity in the oxidation of ethylene at 0 to 20 °C. At an ethylene concentration of 50 ppm, over 99.8 % conversion was obtained at 0 °C, a previously unattained level that remains steady over longer periods and after multiple uses.

The catalyst is made by stirring the support with an aqueous solution of a platinum salt for 18 hours. The support is then dried and heated first under oxygen and then under hydrogen. After this process, the large pores of the silicon dioxide material contain platinum particles with a size of about 2.4 nm. This particle size, as well as the effect of the silica, seem to be particularly favorable for the reaction.

It is proposed that ethylene (C2H4) and oxygen initially react rapidly on this catalyst to form formaldehyde (HCHO), which is adsorbed onto the platinum and then primarily degraded to carbon monoxide (CO) and hydrogen species that in turn react with oxygen species to make carbon dioxide and water. A small amount of formic acid is formed as a byproduct. The especially high activity of the catalyst results from the facile oxidation of CO to CO2 that occurs at platinum on silicon dioxide supports. The precise details of the reaction mechanism are currently under investigation.

About the Author
Dr Atsushi Fukuoka is Director and Professor of Catalysis Research Center, Hokkaido University, Sapporo, Japan. His main specaility is heterogeneous catalysis, in particular catalytic conversion of cellulosic biomass and catalysis of mesoporous materials. He is a council member of the International Association of Catalysis Societies.

Author: Atsushi Fukuoka, Hokkaido University (Japan), http://www.cat.hokudai.ac.jp/fukuoka/english.html

Title: Low-Temperature Oxidation of Ethylene over Platinum Nanoparticles Supported on Mesoporous Silica

Angewandte Chemie International Edition, Permalink to the article: http://dx.doi.org/10.1002/anie.201300496

Atsushi Fukuoka | Angewandte Chemie
Further information:
http://pressroom.angewandte.org
http://www.cat.hokudai.ac.jp/fukuoka/english.html

More articles from Life Sciences:

nachricht Algae: The final frontier
22.06.2017 | Carnegie Institution for Science

nachricht Flipping the switch to stop tumor development
22.06.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

Im Focus: Optoelectronic Inline Measurement – Accurate to the Nanometer

Germany counts high-precision manufacturing processes among its advantages as a location. It’s not just the aerospace and automotive industries that require almost waste-free, high-precision manufacturing to provide an efficient way of testing the shape and orientation tolerances of products. Since current inline measurement technology not yet provides the required accuracy, the Fraunhofer Institute for Laser Technology ILT is collaborating with four renowned industry partners in the INSPIRE project to develop inline sensors with a new accuracy class. Funded by the German Federal Ministry of Education and Research (BMBF), the project is scheduled to run until the end of 2019.

New Manufacturing Technologies for New Products

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Hubble captures massive dead disk galaxy that challenges theories of galaxy evolution

22.06.2017 | Physics and Astronomy

New femto-camera with quadrillion fractions of a second resolution

22.06.2017 | Physics and Astronomy

Rice U. chemists create 3-D printed graphene foam

22.06.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>