is high enough throughout an extensive temperature range, which renders re-oxidation of metallic Ni impossible. In the 2-propanol TPR experiment, the sample is completely reduced to a face centred cubic metal phase, on which a large amount of carbon is deposed, which originates from thermal decomposition processes shown in figures 12 and 13. Phase compositions in the 2-propanol steam reforming settings are relatively similar. At the two lowest oxygen concentrations, very small amounts of metallic Ni are found. After partial oxidation, NiFe2O4, NiO and metallic nickel are found. More nickel is found, when a higher oxygen concentration had been applied, showing, that the formation of larger amounts of reducing agents increases the amount of metal found. At the same time, the oxygen level is much higher than at a 2-propanol:O2 ratio of 1:1 only, which was used for oxidative dehydrogenation and where metal formation was much higher (after two cycles). The diffractograms of samples used in the two acetone steam reforming settings are both showing 80 % NiFe2O4 and 20 % NiO, approximately. After partial oxidation of acetone, the sample composition is 25 % NiFe2O4, 16 % metallic nickel and 59 % carbon. A considerable crystallite growth is found in all samples. The changes of phase composition and crystallite size in the large crystallite size sample are very discrete mostly, confirming the higher reduction temperatures found in H2-and CO-TPR experiments resulting in a n increased resistance to the reducing environments in the various reactions. The only experiments, after which major phase changes occur are the 2-propanol-TPR and partial oxidation of acetone, where complete reduction to a face centred cubic metal phase and carbon deposition and partial reduction to a phase mentioned before and carbon deposition occur, respectively. Carbon deposition is lower than in the smaller crystallite size sample. This trend was found in the CO-TPR experiments as well. The spectra of the adsorption experiment over the smaller crystallite size sample are much stronger in intensity due to the higher surface area most likely and therefore interpretable more easily. A multitude of sources about the assignment of bands occurring during the adsorption and/or oxidation of 2-propanol exists in the literature. The materials mainly addressed there are TiO2, precious metals on carrier materials such as Au/TiO2 and Co3O4. The material coming closest to NiFe2O4 is CoFe2O4 or CoxFe3-xO4 . In the region between 900-1800 cm -1 , bands at 1473 and 1464 cm -1 , 1393, 1381 and 1368 cm -1 , 1267, 1251 and 1235 cm -1 and 1071 cm -1 are assigned to δas(CH3), δs(CH3), δ(OH) and ν(C-O) of gas phase 2-propanol or molecularly adsorbed 2-propanol , bands at 1342, 1161, 1130 and 953 cm -1 to γ(CH) , ν(C-C) , ν(C-O) and Γ(CH3) of adsorbed 2-propoxide, bands at 1022 and 933 cm -1 to vibrations related to acetate from oxidation of 2-propanol residues during the pretreatment and bands at 1555/1547 and 1309/1304 cm -1 to ν(C=O) and νas(O-C-O) of bidentate carbonate . The band at 1342 cm -1 may be related to γ(CH) of acetate as well . The region between 2700-3100 cm -1 shows signals at 2982/2980 and 2972 cm -1 , 2931 and 2889/2887 cm -1 , which are assigned to νas(CH3) of 2-propoxide and gas phase 2-propanol, respectively or ν(C-H) of gas phase and molecularly adsorbed 2propanol and 2-propoxide , respectively and ν(C-H) of 2-propoxide . In the smaller crystallite size sample, the signal at 2972 cm -1 is stronger than in the gas phase spectrum of 2-propanol, possibly showing a higher amount of 2-propoxide than in the larger crystallite size sample, which is in agreement with the other bands stronger than in the larger crystallite size sample and indicative of 2-propoxide. The broad band in the region between 3100 and 4000 cm -1 is related to molecularly adsorbed 2-propanol and is much stronger in the smaller crystallite size sample, demonstrating once more the higher surface area in this sample. Bands at 3658 and 3637 cm -1 are assigned to ν(O-H) of gas phase 2-propanol. The most prominent feature in the IR spectra at reaction conditions at 50 °C, is a signal located around 1570 cm -1 in the small crystallite size sample and around 1550 cm -1 in the large crystallite size sample, respectively. This position can be suggestive of both acetate and bidentate carbonate. Signals were found in the 2-propanol adsorption experiments at these positions as well, which is why they are ascribed to species formed during the pretreatment atmosphere rich in oxygen from the combustion of residual 2-propanol from prior experiments using this agent. Still, it is impossible to find further signals indicative of either species due to limited spectral quality and overlapping with signals of reagents, products or various carbonate species. However, the acetate signals located around 1020 cm -1 , 1640 cm -1 and 1700 cm -1 usually, should not be affected by spectral interference, if present. A shift of vas to lower wavenumbers at higher temperatures in both samples and both 2-propanol:O2 ratios is found. This might point to the formation of different carbonate species or an altered interaction of existing carbonate species with an increasing amount of O-H groups from water formed during the reaction as it has been reported about carbonate formation on different materials in different experimental settings . As the position of potential carbonates' signals differs in the lower and higher crystallinity sample, there might be a different availability and accessibility of water or O-H groups on the samples' surface to interact with adsorbed carbonates. As both samples differ largely in specific surface area and their capacity to adsorb molecules on their surface, it is difficult to estimate, how or if a certain amount of water interacts with adsorbed carbonates and alters the position of the respective IR signals.