18 May, 2018
Scientists don’t often call the focus of their work gorgeous, but this is the exact term that Principal Investigator Professor Shane Telfer uses to describe the metal-organic frameworks (MOFs) he is creating in the lab.
“Under a microscope they look quite beautiful,” says Professor Telfer. “Out of the gloop we use to produce MOFs, emerge these beautiful crystalline forms.”
While they may be nice to look at, MOFs could also provide the answer for storing gases like hydrogen – an alternative to fossil fuels – in large quantities.
MOFs are like 3D sponges. When placed in cylinders they can store hydrogen in much smaller spaces and at a much lower pressure – allowing cars, or even planes, to run on hydrogen.
“MOFs are mostly free space, like an open porous net, with a metal at the corners and an organic component as the rods or linkers,” explains Professor Telfer.
In another win for the environment, MOFs could also potentially be used to absorb and enrich carbon dioxide, thereby remediating climate change.
“One of our MacDiarmid PhD students has run calculations to show that if you pass air through a MOF, you can capture the oxygen,” says Professor Telfer.
So rather than using a bulky cylinder of oxygen, a patient could have a much smaller MOF- infused device. This would be more efficient, cheaper, and have a longer life span.
Professor Telfer has 12 years under his belt working on MOFs. His MacDiarmid Institute collaborators have now begun some blue skies exploration and have come up with new materials and a new process for creating MOFs.
The MacDiarmid team pulls together researchers from all over New Zealand, including Principal Investigator Professor Paul Kruger from the University of Canterbury, Principal Investigator Dr Carla Meledandri from the University of Otago, and Principal Investigator Dr Geoff Waterhouse from the University of Auckland. Professor Telfer says the MacDiarmid MOF team bid successfully for 2018 MBIE Catalyst funds of $1.5 million to work with CSIRO to develop applications of their MOF materials, including new catalysts for eliminating nitrous oxide greenhouse gas emissions.
The team is looking at more efficient ways to make MOFs, and new applications for the materials they discover. To help understand the structure of their materials, the team benefits from collaborations with the electron microscopy lab at Victoria University of Wellington, led by Principal Investigator Professor Thomas Nann.
The team recently published a report in the prestigious Journal of the American Chemical Society showcasing their discovery of a new process to create functional, bimetallic nanoparticles using MOFs as starting materials.
“These kinds of nanoparticles are hard to make,” says Professor Telfer. “Two metals often don’t like getting alongside each other, but using this method you end up with a nanoparticle containing two metals. And they’re catalytically active.”
The catalysts they created were made with very low levels of platinum, which is expensive and rare.
Such processes are important as they can make aniline – an organic compound that is the precursor for many things, including conducting polymers (for which New Zealander Alan MacDiarmid won the Nobel Prize for Chemistry for in 2000).
Professor Telfer says it was a true collaborative effort. Professor Telfer designed the project with Professor Kruger; Dr Hui Yang did the experimental work, including the catalysis studies; Associate Professor Geoff Waterhouse helped characterise the materials; and Professor Thomas Nann and his postdoctoral researcher Dr Siobhan Bradley contributed to the analysis by finding the structure and the composition on the nanoscale.
“That is something that links us. There is this beneficial collaboration that has come out of the Institute: scientists who may not have crossed paths or had the opportunity to talk much science, but valuable connections between them are forged by MacDiarmid,” says Professor Telfer.
Another MacDiarmid Principal Investigator, University of Otago senior lecturer Dr Carla Meledandri uses emulsion droplets as a way to synthesise nanoparticles.
Professor Telfer immediately saw that the idea was perfect for making MOFs.
Instead of the current method of putting the metal and organic parts of a solution in an oven, the MOFs could be fused in an emulsion.
“Dr Meledandri has two types of droplets, which she merges,” says Professor Telfer. “By themselves they don’t do anything, but together they do.”