Abstract
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.