Catalized Diesel Exhaust Fluid or Cat DEF (IMAGE) Southwest Research Institute Caption Catalyzed Diesel Exhaust Fluid (Cat-DEF™) is one of three SwRI-developed technologies recognized by R&D Magazine as one of the most significant innovations of 2021. The Cat-DEF™ technology is a catalyst and surfactant modified diesel exhaust fluid (DEF) that provides improvements in nitrous oxide (NOx) and carbon dioxide emissions by reducing undesirable deposit formation in diesel engine exhaust systems. Credit SwRI Usage Restrictions Images/videos may be used by the media and the public for educational and informational purposes only License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.