A critical perspective on the design and development of metal oxide catalysts for selective propylene ammoxidation and oxidation

The objective of this article is to use the example of the development of metal oxide catalysts for the selective ammoxidation and oxidation of propylene to illustrate successful catalyst design strategies for achieving enhanced yields of acrylonitrile and acrolein, respectively. The processes of catalytic selective ammoxidation and oxidation of propylene are not the only, albeit they are among the most industrially significant, examples of the commercial application of metal oxide selective oxidation catalysts. Other important commercial catalytic processes that use highly developed metal oxide catalysts systems include butane oxidation to maleic anhydride and alkyl aromatic ammoxidation of toluene, xylenes, and picolines (alkyl pyridines) to produce valuable aromatic nitriles including nicotinonitrile which is the precursor for nicotinic acid (niacin) an important B-complex vitamin. Using the example of industrial propylene selective (amm)oxidation, this article surveys the available patents, scientific and technical journals to chronical and analyze the development and advancement of the complex metal oxides from discovery to current state-of-the-art. Recognizing that commercial practices are proprietary, this analysis uses no known company sensitive or confidential information is included in these descriptions. From this analysis a comprehensive catalyst design strategy unfolds that is based on the enabling science of solid state chemistry and the results of the characterization tools it provides. This provides a viable platform to unlock the next level of metal oxide catalyst development with ultra-high selectivity for hydrocarbon oxidation.