Light alkane oxidation over well-defined active sites in metal–organic framework materials

Abstract

The single-step conversion of light alkanes to chemical/energy carriers that can be readily transported over long distances is a critical component in the effort to effectively valorize vast reserves of shale gas resources in the United States and around the world. Catalyst materials traditionally investigated for such applications – although exhibiting promising alkane oxidation performance – typically display a broad distribution of active site speciation within individual formulations, making it challenging to develop generalizable principles guiding the rational design of highly active and selective catalysts. Metal–organic framework materials (MOFs) enable a high level of definition and uniformity in active site structure, as well as a multitude of alternatives in terms of active site coordination environment, thereby potentially enabling a more rigorous understanding of the relationship between structure and catalytic function. This review provides an overview of key examples of MOF-catalyzed C1–C3 alkane oxidation that have been reported in the literature, with an emphasis on active site characterization, reaction mechanisms, and proposed structure–function relationships. Also presented and discussed are critical knowledge gaps and future prospects for this burgeoning (but still nascent) area of research.