Tag Archives: Johan A. Martens

Generating power from polluted air

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I have no idea how viable this concept might be but it is certainly appealing, From a May 8, 2017 news item on Nanowerk (Note: A link has been removed),

Researchers from the University of Antwerp and KU Leuven (University of Leuven), Belgium, have succeeded in developing a process that purifies air and, at the same time, generates power. The device must only be exposed to light in order to function (ChemSusChem, “Harvesting Hydrogen Gas from Air Pollutants with an Unbiased Gas Phase Photoelectrochemical Cell”).

Caption: The new device must only be exposed to light in order to purify air and generate power. Credit: UAntwerpen and KU Leuven

A May 8, 2017 University of Leuven press release (also on EurekAlert), which originated the news item, describes this nifty research in slightly more detail,

“We use a small device with two rooms separated by a membrane,” explains Professor Sammy Verbruggen (UAntwerp/KU Leuven). “Air is purified on one side, while on the other side hydrogen gas is produced from a part of the degradation products. This hydrogen gas can be stored and used later as fuel, as is already being done in some hydrogen buses, for example.”

In this way, the researchers respond to two major social needs: clean air and alternative energy production. The heart of the solution lies at the membrane level, where the researchers use specific nanomaterials. “These catalysts are capable of producing hydrogen gas and breaking down air pollution,” explains Professor Verbruggen. “In the past, these cells were mostly used to extract hydrogen from water. We have now discovered that this is also possible, and even more efficient, with polluted air.”

It seems to be a complex process, but it is not: the device must only be exposed to light. The researchers’ goal is to be able to use sunlight, as the processes underlying the technology are similar to those found in solar panels. The difference here is that electricity is not generated directly, but rather that air is purified while the generated power is stored as hydrogen gas.

“We are currently working on a scale of only a few square centimetres. At a later stage, we would like to scale up our technology to make the process industrially applicable. We are also working on improving our materials so we can use sunlight more efficiently to trigger the reactions. “

Here’s a link to and a citation for the paper,

Harvesting Hydrogen Gas from Air Pollutants with an Unbiased Gas Phase Photoelectrochemical Cell. by  Prof. Dr. Sammy W. Verbruggen, Myrthe Van Hal1, Tom Bosserez, Dr. Jan Rongé, Dr. Birger Hauchecorne, Prof. Dr. Johan A. Martens, and Prof. Dr. Silvia Lenaerts. ChemSusChem Volume 10, Issue 7, pages 1413–1418, April 10, 2017 DOI: 10.1002/cssc.201601806 Version of Record online: 6 MAR 2017

© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

This paper is behind a paywall.

Making diesel cleaner

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A Dec. 10, 2015 news item on Nanowerk announces a new method for producing diesel fuels (Note: A link has been removed),

Researchers from KU Leuven [Belgium] and Utrecht University [Netherlands] have discovered a new approach to the production of fuels (Nature, “Nanoscale intimacy in bifunctional catalysts for selective conversion of hydrocarbons”). Their new method can be used to produce much cleaner diesel. It can quickly be scaled up for industrial use. In 5 to 10 years, we may see the first cars driven by this new clean diesel.

A Dec. 10, 2015 KU Leuven press release, which originated the news item, provides more detail about the research,

The production of fuel involves the use of catalysts. These substances trigger the chemical reactions that convert raw material into fuel. In the case of diesel, small catalyst granules are added to the raw material to sufficiently change the molecules of the raw material to produce useable fuel.

Catalysts can have one or more chemical functions. The catalyst that was used for this particular study has two functions, represented by two different materials: a metal (platinum) and a solid-state acid. During the production process for diesel, the molecules bounce to and fro between the metal and the acid. Each time a molecule comes into contact with one of the materials, it changes a little bit. At the end of the process, the molecules are ready to be used for diesel fuel.

The assumption has always been that the metal and the solid-state acid in the catalyst should be as close together as possible. That would speed up the production process by helping the molecules bounce to and fro more quickly. Professor Johan Martens (KU Leuven) and Professor Krijn de Jong (Utrecht University) have now discovered that this assumption is incorrect. [emphasis mine] If the functions within a catalyst are nanometres apart, the process yields better molecules for cleaner fuel.

“Our results are the exact opposite of what we had expected. At first, we thought that the samples had been switched or that something was wrong with our analysis”, says Professor Martens. “We repeated the experiments three times, only to arrive at the same conclusion: the current theory is wrong. There has to be a minimum distance between the functions within a catalyst. This goes against what the industry has been doing for the past 50 years.”

The new technique can optimise quite a few molecules in diesel. Cars that are driven by this clean diesel would emit far fewer particulates and CO². The researchers believe that their method can be scaled up for industrial use with relative ease, so the new diesel could be used in cars in 5 to 10 years.

The new technique can be applied to petroleum-based fuels, but also to renewable carbon from biomass.

A fifty year old assumption has been found wrong. Interesting, non? In any event, here’s a link to and a citation for the paper,

Nanoscale intimacy in bifunctional catalysts for selective conversion of hydrocarbons by Jovana Zecevic, Gina Vanbutsele, Krijn P. de Jong, & Johan A. Martens. Nature 528, 245–248 (10 December 2015)  doi:10.1038/nature16173 Published online 09 December 2015

This paper is behind a paywall.