Fe2(MoO4)3.xMoO3

https://ac.els-cdn.com/S0926860X00006001/1-s2.0-S0926860X00006001-main.pdf?_tid=a65ec5ae-c604-11e7-ab5e-00000aab0f27&acdnat=1510311073_1b3c8500bf5cf4deb85e447c68b59f39

Answers to your question, search, eg. in my answers (several times I wrote about kinetic studies in batch reactors) or works. Instead of batch reactor (study conversion vs. time) you can use one of gradientless reactors (study of reaction rate vs. concentration).

Regards,

This topic is very broad and wide and I think your question needs to be more specific. There are thousands of papers about that topic.

All the best,

You have to be more specific. Good to focus on Fe-based catalysts as they aremore earth-abundant and less toxic.

Think of iron oxides, some of magnetic type, that can provide you recovery and recycling capabilities as well.

I attach a tutorial review we published some time back.

Dear Rajender S Varma . Thank you a lot for this useful file.

Dear Valentin

You can find a vast number of books and papers for estimation of heterogeneous catalyst activity in the liquid phase process; for example, the recent ones:

· Dmitry Murzin, Tapio Salmi. Catalytic Kinetics, Elsevier, 2016, eBook ISBN: 9780444634634, Paperback ISBN: 9780444637536,

· Michel Boudart,‎ G. Djega-Mariadassou. Kinetics of Heterogeneous Catalytic Reactions. Princeton University Press, 2016, ISBN-10: 0691640483, ISBN-13: 978-0691640488.

I am adding a few comments, which maybe help you:

· Performance of L-S and G-L-S systems (G-phase, for example hydrogen, or oxygen) is strongly affected by mass transport. Usually, research endeavour is to reach a kinetic regime, i.e. determination of the rate by surface chemical reactions. This requires an intensive mixing of the liquid (and gas-vapour phase) phase, and as much as possible little catalyst particles to minimize effects of internal diffusion.

· Intensive mixing causes an attrition of the catalyst. You have to check the texture of catalyst before and after catalytic tests and to perform catalytic tests with the used catalyst (at least two times recycling)

· Exothermic reactions usually contribute to the deactivation of a catalyst. In order to minimize this effect, dilution of the reaction mixture is advised. The best way is to use a product as a solvent, if possible; e.g. the hydrogenation of nitrobenzene in a solution with aniline.

· Plan experiments (sampling) in such a way to “cover the conversion curve” from the point close to zero up to 100 %, or equilibrium.

· Take into account a decrease of the liquid phase volume in the batch reactor during sampling of the reaction mixture.

· When a gas reactant (hydrogen in case hydrogenations, oxygen in case of oxidation) is used, monitoring of the gas consumption nicely completes description of kinetics.

· Be careful with keeping isothermal regimes (according to plan of experiments). Treatment of data from non-isothermal regimes is possible but it is more arduous than isothermal data.

· Use reliable analytical methods for quantitative evaluation of content components in the reaction mixture (mass %; area percentage from GC is not suitable for a description of kinetics).

· The simplest way how to characterise a catalyst activity is the initial reaction rate, however be careful with the activation of the catalyst at the start of the experiment.

· If you like to obtain a more complex description and your data are not affected by mass transport, the reaction system is described by ordinary differential equations. You can decide for the power-low kinetics or mechanistic models. The most frequently used: Houghen Watson Langmuir Hinshelwood, Elley-Ridell, Mars and van Krevelen types for oxidation process; see the literature above).

· To obtain kinetic parameters, usually the least square method is used. A minimization by some simple procedures under Excel is possible; however for example Matlab and other user friendly programs offer a much higher comfort. I am sure that your colleagues have other specialised programs, which should enable to treat your data.

· Be careful with transfer of kinetic parameters from a batch test to a continuous process if intensive mixed reactors are planned to be used. For solution of this problem, the starting reaction composition close to the output from a continuous reactor should help validity of kinetic data from the batch tests.

Have a good luck in your research.

Yours sincerely,

Milan Kralik

�

Additional, very important comment:

check leaching of metals

In catalyst testing, the type of reactor is important, usually - batch reactor (for liquid phase processes) and fixed- bed tubular reactor, fluidized- bed reactor or one of gradientless reactors (for gas phase processes). It is important to perform the experiments in varios temperature. It is enough to carry out an experiment for one or two molar ratios of substrates corresponding to stoichiometric relations (it is not enough for kinetic study). You should also pay attention to the possibility of catalyst deactivation. Influence of external diffusion can be eliminated by more intensive mixing (batch reactor) and by increased of flow rate (tubular type reactor). Influence of internal diffusion can be eliminated by reducing of particle size. Catalytic test should provide information on conversion, selectivity and possible deactivation. Regards,