Catalytic oxidation of organic pollutants is an attractive and sustainable method of water purification. This paper focuses on discussion of catalytic activity, selectivity, and stability in catalytic wet air oxidation and advanced oxidation processes. The emphasis is on exploring the potential of applying relevant catalytic knowledge and information outside the field of water remediation, such as in aqueous phase biomass processing and catalyst design, toward meeting the challenges in these processes. One example is to explore utilizing the interfacial perimeter sites of a supported metal catalyst to modify the catalytic properties. Another example is to improve catalyst stability from metal leaching by using overcoats of oxide or carbon and by understanding the phase transformation of the supported oxide. This paper also examines the prospect of harvesting the chemical energy stored in the organic contaminants in polluted water to catalytically generate H2O2 in situ for the advanced oxidation process, thereby eliminating the use of costly oxidants.