The 12 catalysts were applied in ethane, propane, and nbutane oxidation reactions. The choice of materials includes the industrial state-of-the-art catalyst for n-butane selective oxidation to maleic anhydride (MAN), vanadyl pyrophosphate (VPP or VPO) (VO)2P2O7, as well as the widely studied MoVTeNbOx, mixed-metal oxide "M1" phase catalyst. Following the structural diversity of bulk catalysts studied in oxidation catalysis, both amorphous and crystalline materials, as well as single-phase compounds and phase mixtures were included in the present study. Catalyst synthesis. The synthesis of the catalyst precursors is described in the Supporting Information (SI, the synthesis is also documented in a local database and the corresponding sample ID's are summarized in Table ). A rather large batch size of 20 g was specified in order to provide enough material to carry out all three reactions as well as the comprehensive materials characterization on one and the same batch. The synthesis includes thermal treatments, pressing and sieving. The so-obtained fresh samples are finally subjected to a rapid catalyst activation under harsh reaction conditions. The resulting samples are referred to as activated samples.