More reaction sites increase activity
XAFS showed that the georgeite was incredibly disordered initially, and the final structure at the end of its evolution following calcination and reduction was completely different to that of zincian malachite. Moreover, the catalyst derived from georgeite was composed of much smaller copper and zinc oxide particles than that of zincian malachite, with a greater degree of interaction between the two phases. This observation was supported by environmental transmission electron microscopy performed at the Technical University of Denmark.
Dr Wells summarised the main findings: “We saw that georgeite was more disordered and had smaller particles than zincian malachite, which we believe led to a higher number of reaction sites and therefore more copper and zinc interactions, making it a very active catalyst.” In fact, georgeite proved to be more active than zincian malachite for LTS and methanol synthesis, so this newly-synthesised mineral has a very promising future.
Dr Wells concluded, “The reason this is such an important piece of work is because this is a very important industrial reaction that makes an awful lot of material, and we were able to show improvements over the conventional catalyst.” He added, “The hydroxycarbonate minerals make up the lion’s share of catalysts for LTS and methanol synthesis and georgeite could easily become one of those widely-used catalysts.”
The team now intend to study georgeite in action during LTS and compare it directly with zincian malachite. They hope to combine XAFS with infrared light to observe how the nanoparticles change over the course of the reaction, and to monitor the LTS reaction on the surface of the mineral.
To find out more about using XAFS on B18, or to discuss potential applications, please contact Principal Beamline Scientist Dr Giannantonio Cibin: firstname.lastname@example.org
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