Achieving Atomic Dispersion of Highly Loaded Transition Metals in Small‐Pore Zeolite SSZ‐13: High‐Capacity and High‐Efficiency Low‐Temperature CO and Passive NO x Adsorbers

The majority of harmful atmospheric CO and NO x emissions are from vehicle exhausts. Although there has been success addressing NO x emissions at temperatures above 250 °C with selective catalytic reduction technology, emissions during vehicle cold start (when the temperature is below 150 °C), are a major challenge. Herein, we show we can completely eliminate both CO and NO x emissions simultaneously under realistic exhaust flow, using a highly loaded (2 wt %) atomically dispersed palladium in the extra‐framework positions of the small‐pore chabazite material as a CO and passive NO x adsorber. Until now, atomically dispersed highly loaded (>0.3 wt %) transition‐metal/SSZ‐13 materials have not been known. We devised a general, simple, and scalable route to prepare such materials for Pt II and Pd II . Through spectroscopy and materials testing we show that both CO and NO x can be simultaneously completely abated with 100 % efficiency by the formation of mixed carbonyl‐nitrosyl palladium complex in chabazite micropore.