Heating, ventilation, air-conditioning, and refrigeration (HVACR) are essential to the quality of life for all humans. HVACR systems are widespread throughout society, enabling transportation and preservation of fresh foods, storage of medicines, and cooling of buildings. However, most refrigerants used today are hydrofluorocarbons (HFCs), which have high global-warming potential (GWP), with 2000-4000 times the impact of CO2. Combined with high leak rates (direct effect -- 50-90% of refrigerants leak into the atmosphere) and high energy consumption (indirect effect -- 20-40% of U.S. residential and commercial building electricity usage comes from HVACR), HFCs account for 7.8% of total greenhouse-gas emissions.To address this challenge, a new NSF Engineering Researc