Integrating molecular binding groups into scalable materials
Historically, adsorbent design has maximized single-component adsorption capacities under ideal conditions. In separations with dilute and impure feeds, selectivity over competing species becomes paramount. The target is often present at much lower concentrations than other components (e.g., 0.04 vol.% CO2 versus 2 vol.% H2O in air), necessitating high adsorptive selectivity to overcome the concentration disparity. The target also coexists with reactive or fouling species (e.g., ozone in air, organic matter in wastewater), and selective adsorption is necessary to prevent detrimental degradation. Selectivity is challenging in environmental feeds because many species have nearly identical size, charge, and binding energy, rendering traditional enthalpy-based selectivity strategies ineffective. To overcome these issues, we design scalable separation materials with alternative selectivity mechanisms, including entropic, kinetic, and desorptive selectivity.
Translating structure into process models through characterization
Iterative material-process design requires robust process models that translate changes in material structure and operating conditions into changes in performance. Current models face three limitations that prevent rapid iteration between materials and processes:
- Measurement gap: Conventional experiments yield average, extrinsic parameters that obscure local behavior (e.g., no differentiation between adsorption sites in adsorbents) and depend on operating conditions;
- Modeling gap: Process models rely on empirical correlations without a connection to material structure, resulting in no predictive framework to translate between structural changes and process performance;
- Time gap: Material stability is a critical determinant of process viability, yet practical measurements do not capture long-term performance, and conventional models lack sufficient intrinsic material information to predict it.
To bridge these gaps, we quantify material evolution using advanced characterization methods and incorporate the mechanistic insights into process models that connect material structure to long-term performance.
Synthesizing processes to meet system-level targets
Separation techniques have historically been developed in parallel, with each field focusing on optimizing a single approach for its specific applications. Limited attention has been given to the strategic integration of multiple separation mechanisms (e.g., charge, affinity, solubility, volatility), driving forces (e.g., chemical potential, electric potential), and technologies (e.g., selective adsorbents, membranes, electrodes), which could reduce the energy requirements of dilute separations and enable performance that is not achievable with conventional, single-approach systems. Further, separations and catalysis are often addressed as distinct challenges rather than as an interconnected solution. Designing separations and catalysis together as reactive separations enables process intensification and allows separations and conversions that would be infeasible if designed independently. We design and assess (1) the integration of multiple separation technologies and (2) the integration of separations and catalysis, both within the same material and as coupled unit processes.
