Category Chemistry/Nanotechnology

Photon upconversion: Energy transfer between the molecules is based on electron exchange (Dexter electron transfer). Credit: Illustration: Michael Oldenburg

The upconversion of photons allows for a more efficient use of light: 2 photons are converted into a single photon having higher energy. Researchers at KIT now showed for the first time that the inner interfaces between surface-mounted metal-organic frameworks (SURMOFs) are suited perfectly for this purpose – they turned green light blue. The result opens up new opportunities for optoelectronic applications such as solar cells or LEDs.

Metal-organic frameworks (MOFs) are highly ordered molecular systems that consist of metallic clusters and organic ligands...

Modeling how methanol interacts with platinum catalysts inside fuel cells in realistic environments becomes even more complicated because distances between the atoms can change as molecules dance near the charged surface. Credit: Manos Mavrikakis

Using a unique combination of advanced computational methods, University of Wisconsin-Madison chemical engineers have demystified some of the complex catalytic chemistry in fuel cells – an advance that brings cost-effective fuel cells closer to reality. “Understanding reaction mechanisms is the first step toward eventually replacing expensive platinum in fuel cells with a cheaper material,” says Prof. Manos Mavrikakis.

Fuel cells generate electricity by combining electrons and protons — provided by a chemical fuel such as methanol – with oxygen fr...

Nanofiber mat electrode (John Russell / Vanderbilt)

The project is part of a $13 million Department of Energy program to advance fuel cell performance and durability and hydrogen storage technologies announced last month. The $4.5 million collaboration is based on a new nanofiber mat technology developed by Peter Pintauro, the H. Eugene McBrayer Professor of Chemical Engineering at Vanderbilt, that replaces the conventional electrodes used in fuel cells. The nanofiber electrodes boost the power output of fuel cells by 30% while being less expensive and more durable than conventional catalyst layers...

Individual crystals of synthetic zhemchuzhnikovite, prepared by Igor Huski?, McGill University. Credit: Igor Huski?, Friš?i? Research Group, McGill University

A surprising discovery reveals that MOFs also exist in nature – albeit in the form of rare minerals found so far only in Siberian coal mines. Metal-organic frameworks are human-made materials introduced in the 1990s, and researchers are working on ways to use them as molecular sponges for applications such as H storage, C sequestration, or photovoltaics.

The finding “completely changes the normal view of these highly popular materials as solely artificial, ‘designer’ solids,” says Tomislav Friščić, an associate professor of chemistry at McGill University in Montreal...