Producing propene by the oxidative dehydrogenation of propane (ODH) has become an attractive and feasible route for bridging the propene production-demand gap, either as a complementary route of the existing oil-based processes or as a new alternative from propane separated from natural gas. The industrial application of propane ODH has not succeeded so far due to low propene yields. Therefore, propane ODH has been extensively investigated in recent decades using different catalysts and reaction conditions. Although several important aspects have been discussed in previous reviews (e.g., supported vanadium oxide catalysts, bulk catalysts, productivity toward propene, etc.), other relevant aspects have not been addressed (e.g., support effects, loading effects, vanadia precursor or catalyst synthesis methods, surface impurities, structure–reactivity relationships, etc.). In this review, we endeavor to cover the majority of the publications with an emphasis on the following: (1) catalyst synthesis: to focus on the influence of synthesis methods on the final vanadium oxide surface species, (2) catalyst characterization: to identify the molecular structures of the supported vanadium oxide species as well as the oxide support surface physical and chemical characteristics, (3) kinetics: to understand how reaction rates depend on variables such as concentration of gas-phase reactants and temperature, (4) structure–activity relationship: to examine the influence of the concentration as well as molecular structures of the surface vanadium oxide species on the reaction kinetics, and (5) reaction mechanism: to use the structure–activity relationships as well as kinetic studies plus theoretical calculations to corroborate and/or propose reaction pathways that account for the overall ODP reaction mechanism

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In part 1 of this series (ref 1) we presented a qualitative thermodynamic description of the phase behavior of quaternary mixtures of water, nonpolar solvents, nonionic amphiphiles, and salts. The phase behavior of such mixtures follows general patterns that are essentially determined by the phase diagrams of the corresponding binary and ternary mixtures. In this paper (part 2) the nonionic amphiphiles are replaced by ionic amphiphiles. The general patterns of these mixtures, in particular the phase sequence with rising temperature, are inverse to those with nonionic amphiphiles? It is shown that this inverse behavior originates from the difference between the phase diagrams of binary H20-nonionic amphiphile and those of H20-ionic amphiphile mixtures.

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