The metal–organic framework CuI-MFU-4l reacts with NO, initially forming a copper(I)-nitrosyl at low pressure, and subsequently generates NO disproportionation products CuII–NO2 N2O. thermal stability of MFU-4l allows NOx to be released from the temperatures greater than 200 °C. This treatment regenerates original CuI-MFU-4l, which can engage in subsequent cycles disproportionation.