Medium Temperature Intercalation (MTI) through Microwave Irradiation to Access Catalytically Relevant Metastable Chevrel Phases, MMo₆X₈ (M = Ag, Sn; X = S, Se)

The demand for large scale sustainable energy solutions for an energy landscape evolving posthaste calls for the development of transformative materials with the ability to mediate sustainable renewable energy conversion. Chevrel phases (CPs), M_yMo₆X₈ (M = alkali, alkaline, transition, post-transition, and lanthanide metals; X = S, Se, Te) have shown promise as electrocatalysts for the hydrogen evolution reaction (HER), the reduction of carbon dioxide (CO₂R), and the oxygen reduction reaction (ORR). However, efficient, and selective electrochemical conversion is hindered by achieving controlled bonding affinity of key intermediates. CPs offer a unique platform to probe structure function relationships between active sites and key intermediates in part to their highly tunable framework. While classical high temperature synthesis methods can be used to access thermodynamically stable CPs, the same methods can yield impure material for metastable CPs. Medium temperature intercalation (MTI) can be used to diffuse cations of interest into existing Mo₆X₈ framework to access pure phase metastable CPs. This work reports a facile synthesis procedure developed using a commercial microwave to synthesize SnMo₆X₈ and AgMo₆X₈ (X = S, Se), full characterization of the materials, and highlight X-Ray Absorption Near Edge Structure (XANES) and Extended X-Ray Absorption Fine Structure (EXAFS) data to gain insight on local electronics and structure.