 One of the big pollutants in diesel engine exhaust is NOx, or nitrogen oxides. And these pollutants need to be converted into environmentally benign chemicals like nitrogen and water. The heart of the system is selective catalytic reduction unit, SCR, and inside this module the molecules of NOx and ammonia react and ultimately producing essentially nitrogen and water and in many cases the exhaust gas coming out of the tailpipe of the system is cleaner than surrounding urban air. And in our discovery what we found out was one key step of how the catalyst actually works. Copper sites which are located on the zeolite catalyst are mobilized and form pairs during the reaction to activate oxygen. And that turns out to be a key bottleneck in the entire reaction that limits the effectiveness of the catalyst, especially at lower temperatures. These findings in the research that led to it weren't even possible 10 years ago because it required a lot of state-of-the-art techniques to image and observe the catalyst while it was working and to model the catalytic performance using supercomputing powers and techniques that weren't available 10 years ago. And so through a combination of research that was done at DOE, Department of Energy Sponsored National Laboratories, our academic collaborators, and our industrial collaborators we were able to combine information of how the catalyst actually behaves during operation to come up with this discovery. We highly value our partnership with Purdue and Notre Dame because both industry and academia play an important and complementary role in the overall process of innovation for cleaner environment. Our colleagues in the academia understand the processes at a deeper molecular level. We in industry use those findings to build more capable systems which can work better, longer, more effectively for the customer. And so one of the challenges going forward is how do we reduce NOx emissions even further to meet new more stringent regulations that might be coming out to enable more engine-efficient vehicles that will normally operate under lower catalyst temperatures. And in order to do that we need to find new ways to make catalysts accelerate and go beyond the bottlenecks that currently limit the process.