The present invention provides systems and methods for facilitating contact between a liquid and a fluid. Such systems and methods may allow efficient removal of components from the liquid without using undesirable reducing agents. In this regard, the disclosed embodiments provide for the purification of a liquid by passing the liquid and a fluid through a porous medium. The porous medium facilitates mixing of the liquid and the fluid. A partial pressure differential of the component between the liquid and the fluid facilitates the transfer of the component from the liquid to the fluid in the mixed liquid and fluid. One embodiment of the invention relates to a method of purifying a liquid. The method includes passing a liquid, such as a fuel, and a fluid, such as a non-reactive gas, through a porous medium, the liquid containing a component, such as oxygen gas, therein. The passing causes mixing of the liquid and the fluid and transfer of at least some of the component from the liquid to the fluid. The method also includes separating the liquid and the fluid, the separated fluid including at least some of the component. In addition, the present invention provides systems and methods for catalytically interacting one or more reactants and uses thereof, such as removing contaminants, or components, from or adding supplements to liquids. The contaminants may be undesirable components to be removed from a liquid, and supplements may be desired component or components to be added to the liquid, for example, each of which is referred to herein as “component”. The method for the catalytic conversion of a plurality of reactants to produce one or more products therefrom includes passing the plurality of reactants through a catalytically active porous medium, the passing causing mixing of the plurality of reactants and chemical conversion of one or more of the reactants, thereby producing one or more products therefrom.