There is a lot of debate around what catalysts lead to successful LENR, one compound that seams to crop up again and again is various Iron Oxides - Bob Higgins has talked about the importance of this and has even published a way to process Nickel and Iron Oxides into what may be part of an effective LENR fuel mix.
With respect to the recent report by Ólafsson and Holmlid, Ecco mentioned this
"Holmlid used Shell 105 catalyst (Fe2O3-K based with >8% K content) - and only that (!!) - as an ultra-dense Rydberg state Deuterium generator because it's convenient to use, cheap and apparently because it works out of the box without further treatment (as also confirmed by Sveinn Ólafsson on LENR-Forum)."
So there is an off-the shelf catalyst that just works for production of ultra-dense Rydberg state Deuterium - well that is all very well - but how does that teach us anything about what goes into making a catalyst and why?
Well, this paper from early 2010 (before Rossi's first demo), written by Sreelekha Benny, Department of Chemistry, University College London in the Johnson Matthey Technology Centre has a great discussion on Iron Oxide catalysts and dopants, note that Parkhomov had nearly 3.7% Mn and over 20% Al in his fuel by atom%
From page 102
Doping magnetite with Al3+ produces the most negative defect energy of -4.63eV but from page 104 you can see that Mn3+ has the lowest solution energy.
From page 111
Look at where Al and Mn cation dopants sit on the plot
From page 116
"It has been reported that Al2O3 exists as a separate phase in the hematite bulk with a high thermal stability and that the catalytic activity increases with temperature"
From page 122-123
"The ions with similar radii as Fe3+ such as Cr3+, Mn3+, V3+ and Ti3+ possess similar solution energies and they form solid solutions in the bulk of hematite, whereas Al3+ is soluble in the surface. The bigger ions, Y3+ and La3+ would be expected to form separate oxide layers."
Note that Al3+ is the only dopant soluble in the surface.
Again, from page 123
"Finally by comparing all these energies, Al3+, Mn3+ and Ti3+ could be suitable alternatives for Cr3+. However, Ti3+ is not considered due to its anticipated electron transfer with Fe3+ and a tendency to remain in the Ti4+ oxidation state. As Al3+ is harmless and the behaviour of Mn3+ is similar to Cr3+, these two dopants have been chosen for further study."
So, the suggestion by this author is to only study Al3+ and Mn3+ which as said above, is both present in Parkhomov fuel
In the next section they compare these two as dopants with the problem child Cr, the stability and the effect of magnetic fuel in ferro and para magnetic states.
Very interestingly, on page 149
"To conclude this part, the Fe-Al-O solid solution is meta-stable with respect to the separated phases and the mixed solution will only exists at very high temperature. The calculated results verify the results reported by some authors18,21 that the solution is stable above 1600K."
From page 151
"In the preparation of active WGS catalysts, the precursor material, hematite is reduced to magnetite."
Could the initial slow release of H2 from LiAlH4 perform this function if hematite is included?
From page 174
"The Al3+ - doped system has the most disorder at low temperature, while the Mn3+- doped system shows the most extensive disorder at high temperatures."
From page 202
"Aluminium shows a particular tendency to promote oxygen vacancies even if they are in the tetrahedral sites, suggesting that the presence of aluminium will enhance the surface [catalytic] reactivity by producing oxygen vacancies more easily."
From Page 203
"Addition of impurities affects the stability of the surface; for example, the presence of aluminium and divalent manganese increases the surface stability, whereas, chromium, aluminium and manganese in their trivalent oxidation state should make the surface more active by promoting oxygen vacancy formation. Aluminium-doped magnetite leads to highly stable surface encouraging large surface area. "
From page 207
"It is generally accepted that the role of chromium in the WGS reaction is to prevent sintering, increase the surface area of the catalyst and suppress the over-reduction of the active catalyst"
Could Aluminium play a similar anti-sintering role on Nickel also?
In fact, could any of the above work in a similar way with Nickel, but doesn't that take us back to Raney-Nickel?
And with the addition of Lithium, what compounds and structures are made with Iron Oxide, manganese and Aluminium - maybe the battery business has the answers?