In particular, the kinetic analysis of the reactions/processes concerning the effects of temperature as well as gas-reagent pressure on the intensity of physico-chemical interaction between solid and gas; these reactions/processes are common in pyrometallurgy (e.g. 4FeS2 + 11O2 = 2Fe2O3 + 8SO2 and similar), high-temperature corrosion of non-oxide ceramics (e.g. TiC + 2O2 = TiO2 + CO2, ...), hydrogen storage (e.g. Li3N + 3H2 = 3LiH + NH3, ...) and somewhere else, but my interest is mainly connected with bulk (not powder, as formal kinetics is different!) solids interacting with gases
Dear Igor, I know that Jan-Dierk Grundwaldt (presently at KIT, Karlsruhe, Germany) did quite some studies exactly of the type you are interested in. Check his publication record under http://www.itcp.kit.edu/grunwaldt/75.php, maybe that you will find some relevant material! Good luck, and best regards, Dirk
Thermodynamics study could be realised using software HSC Chemistry. This is very sw good tool for evaluation of solidus-gasus reaction thermodynamic.
Thanks, Radovan. However, there is no problem with thermodynamics in this area. Everything is clear with it, but not - with the kinetics, which is sometimes absolutely less-common... Concerning HSC Chemistry I would like to warn you that it is not good for non-stoichiometric compounds. Maybe, you remember that, for example, titanium carbide TiCx exists from TiC0.48 to TiC0.99, so you need to calculate everything taking into account the value of "x" that is not possible in HSC Chemistry, unfortunately...
Dear Dirk, unfortunately, I have not found anything on your link ( http://www.itcp.kit.edu/grunwaldt/75.php) that would be connected with the topic I am asking for... The works there are mainly devoted to catalysis, but not to solid-state gas-exchange reactions.
Dear Igor, I agree. It is necessary to be carefull to use HSC in the case of non stochiometric compounds. It si possible to use your own data. Some non-stochiometric compound are saved in the HSC database also (FeO1-x wustites e.g.). There is Dictra-Thermocalc for kinetics calculations. It could be usfull to look at the JMatPro with Ti database. I have JMatPro without Ti.
I've done the same plus taking into account some original works on thermodynamics of non-stoichiometric compounds (e.g. the works by Turchanins on transition metal carbides)
However, I am looking for an analytical solution in kinetics (!) for some gas-exchange reactions/processes. It looks absolutely unusual, but apparent activation energies and pressure exponent coefficients can change their signs there! So, the higher rates of atoms mobilities results in lower (!) chemical reactivity due to specific properties of reaction products...
Paper on Isotopic exchange on Ca(BH4)2 to form Ca(BD4)2 and back to Ca(BH4)2 shine some light on kinetics of a solid gas reaction. Rate of such reaction is carefully monitored via IR spectroscopy. I suppose this should answer some of your queries. http://pubs.acs.org/doi/abs/10.1021/jp5082609 .
Dear Manish, Sorry, but this is an isotope exchange reaction/process, but not a chemical reaction at all. This is completely different as you have no scales of products and no solid-solid phase boundaries... In the accordance to physical chemistry laws you have the only one (!) solid phase Ca[B(H/D)4]2 and the chemical (!) composition of your solid phase does not change.
For the chemical reason there is no difference between Ca(BH4)2 and Ca(BD4)2, as this is the same physico-chemical solid phase (there is only one chemical element - hydrogen and there is no interphase between Ca(BH4)2 and Ca(BD4)2!)... You know that in the nature everywhere H and D are together with the general natural ratio H/D, so all the properties of this phase in handbooks are given taking into account this ratio. The process Ca(BH4)2 (s) + D2 (g) = Ca(BD4)2 + H2 (g) is extremely priminitive, as it is a typical isotope exchange process, but not a chemical reaction... Although, certainly you can use the elements of chemical kinetics to describe your system behaviour, but you have studied in your work - the physical process, not - chemical! There are also many different diffusion processes, which are not chemical reactions as well! You need to read the definition of "chemical reaction" term in textbooks properly...
Dear Oleksandr,
Thank you very much, but this article is a thermodynamic calculation... Nothing else! However, I am looking for anomalous kinetics in similar reactions, when higher temperatures are corresponing to the lower degree of gas-solid interaction. By the way, it is a bit strange for me that thermodynamics of the Fe-C-O system is still attractive for reseachers in 21st century...
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