The Permian Basin in West Texas and Eastern New Mexico is a rich resource for domestic energy production. Co-produced with much of the oil harvested in this region is natural gas (predominantly methane, a volatile gas and potent greenhouse gas). Because this region is located far from major consumers of energy and because pumping and transporting a volatile gas like methane hundreds of miles is not economically viable, the methane produced in excess of what can be used locally for power is often flared as waste, contributing carbon emissions to our atmosphere and representing a lost economic opportunity of the value of the natural gas itself. Current natural gas valorization routes including syngas production rely on a large scale to be economically competitive and are thus not attractive options for wellhead-scale producers such as those in the Permian Basin. Therefore, there is a critical need to develop economically viable methane valorization strategies for wellhead-scale producers.

Methane dehydroaromatization (MDA) is a direct methane conversion technology that converts methane into small aromatic molecules (predominantly benzene) with co-produced hydrogen. While this technique is economically competitive at wellhead scale in theory, it is challenged by thermodynamic limitations (necessitating high reaction temperatures) and rapid catalyst deactivation. The most-studied catalysts for MDA are zeolite-supported molybdenum species, and we are actively studying these catalysts and their transformations under reaction conditions to understand fundamental processes in MDA including catalyst activation, evolution, and deactivation. This work is paving the way for next-generation catalysts with longer time-on-stream to unlock the potential of the stranded natural gas resources in West Texas.

Membranes are materials that can selectively allow some molecules to pass through while excluding others. A common way membranes operate, and a simple way to understand them, is to think about a sieve with small holes (such as a kitchen sifter or a strainer) that allows small particles or liquids to pass through but retains larger particles on one side. Conventional membrane materials are made of polymers, large and typically disordered molecules that form a dynamic network of pores of various sizes that are not perfectly size-selective, leading to a selectivity-permeability trade-off. Membrane materials with additive nanoporous particles can make the pore size network more regular and simultaneously introduce chemical features that enable very specific interactions beyond what would be achievable in a disordered material. These mixed-matrix membrane (MMM) materials can overcome classical membrane performance limits while simultaneously overcoming an application challenge for the nanoporous filler particles - nanoporous materials are typically synthesized as powders and need additional support or structure before they can be applied in typical processes.

Therefore, the synergy of MMMs presents an opportunity to improve membrane material selectivity-permeability performance while simultaneously overcoming a synthesis challenge for nanoporous materials. Our lab is studying polymer-MOF mixed-matrix membranes for various applications, focusing on understanding and optimizing the polymer-MOF interface in these materials to unlock new design spaces and motivate development of materials able to achieve difficult separations more effectively with lower energy input.

Cleanliness and safety of our water resources is a major concern in West Texas and nationally, and contamination of our (ground)water from a variety of sources presents a challenge for which remediation strategies are necessary. While many contaminants are fairly easy to separate from water using conventional treatment strategies, some are quite difficult to separate and are persistent in water while presenting health concerns even in small amounts. Among water contaminants, per- and polyfluorinated alykyl substances (PFAS), so-called "forever chemicals" are a concern because are difficult to separate from water and they do not break down under environmental conditions and therefore persist and accumulate in groundwater resources. Just as PFAS accumulate in water, they accumulate in organisms when consumed and they have been linked to various negative health outcomes. Relatedly, chlorinated volatile organic compounds (CVOCs) are also a concern as contaminants in water. Despite limited solubility, they still exist in water at concentrations of concern to human health. Both of these classes of materials rose to prominence in usage in the mid-to-late 1900s and have led to widespread water contamination and the need for remediation of contaminated water resources.

A promising class of macrocyclic molecules (including cyclodextrins, pillararenes, and resorcinarenes) has presented a chemically tailorable platform of materials capable of selectively separating PFAS and CVOCs from water under conditions that present challenges for other separation strategies. We are partnering with collaborators to engineer new materials from this family of sorbents capable of healing contaminated water sources and removing persistent and harmful chemicals from the environment.