Influence of Hydrogen and Oxygen Impurities on Platinum-Catalyzed Acetylene Hydrochlorination

High Resolution Image Download MS PowerPoint Slide Platinum (Pt) nanostructuring is a powerful strategy for tuning adsorption properties and reactivity in vinyl chloride monomer (VCM) synthesis. To ensure relevance beyond ideal conditions, catalyst performance must be evaluated under more realistic acetylene (C 2 H 2 ) feeds containing unavoidable impurities such as oxygen (O 2 ) and hydrogen (H 2 ), which can impair the performance through competitive adsorption and active site modification. Herein, we study the behavior of Pt single atom (SA) under multicomponent feeds containing H 2 and O 2 . Pt SA maintains high activity in the presence of H 2, showing full VCM selectivity and no hydrogenation products, owing to their high affinity for HCl. In contrast, cofeeding O 2 leads to a drop in VCM yield of up to 80%, indicating pronounced inhibition. This is proven by O 2 -desorption profiles and DFT simulations, which show increasingly favorable O 2 adsorption upon dechlorination, resulting in oxidative site blocking. These results highlight the importance of maintaining the atomic dispersion of Pt for sustaining selective and robust reactivity under realistic conditions.