M-STAR will address scientific questions pertinent to synthetic chemistry of MXenes, specifically the ability to synthesize MXene compounds by methods other than by etching MAX phases, control of MXene lateral dimensions and surface terminations, and methods for the synthesis of hybrid organic-inorganic MXenes with covalently bounded organic and inorganic components. Direct methods for the synthesis of MXenes include new solid-state and solid-gas reactions, chemical vapor deposition, and salt-assisted templating. In characterizing basic properties of their surfaces and edges, we will establish methods for the synthetic control of MXene sheet size. Finally, hybrid organic-inorganic MXenes (h-MXenes) show great potential to unite the tailorability of organic molecules with the unique electronic properties of inorganic 2D solids. We envision a modular and flexible series of MXene materials based on a list of synthetically accessible and thoroughly investigated MXene compounds.

M-STAR is particularly interested in impactful reactions, with a focus on chemical transformations central to a sustainable carbon-neutral economy, such as hydrogen storage and evolution, reduction or oxidation of ubiquitous feedstocks such as CO₂, N₂, CO, CH₄, and other hydrocarbons into valuable products, as well as large scale industrial transformations of commodity chemicals. Our goal is to understand how the synthetic methodology developments and structure-function relationships above underpin the reactivity and catalytic properties of MXenes. We propose that while charges and energy can be efficiently shuttled within the carbide or nitride 2D layer, the surface groups can be precisely tuned to deliver the desired reactivity. Importantly, molecular modification of MXene surfaces will enable unique atomistic control over catalytic microenvironments and reactivity.