MOF Polymer Composites Exhibit Faster Nitric Oxide Catalysis than MOF Crystallites

Metal-organic frameworks (MOFs), a class of crystalline solids, show promise for application as heterogeneous catalysts. Applying MOFs in industrial settings usually requires that unprocessed MOF powder be immobilized within a continuous phase, such as a polymer; however, it is unknown in general if this immobilization impacts MOF catalyst behavior. Therefore, it is necessary to directly compare unprocessed MOF powders and MOF-polymer composites as catalysts. Herein, we study the biomedically important release of nitric oxide (NO) from endogenous S-nitrosoglutathione (GSNO) catalyzed by the unprocessed powder and polymer composite forms of H3[(Cu4Cl)3(BTTri)8] (CuBTTri). The NO release system is especially appropriate as CuBTTri has found real-world application in the field of biomedical materials. The results show, in this system, that the rate of NO generation changes when a CuBTTri polymer composite is the catalyst as opposed to the unprocessed MOF powder. Hence, findings for MOF powder catalysts may not always translate to MOF-polymer composites.