Hydroxy- or chlorine-anchored Pt single-atom in Al₂O₃: Which is better for propane dehydrogenation?

Platinum-based single-atom catalysts (Pt-1 SACs) can significantly improve the catalytic activity for propane dehydrogenation (PDH) because of their elevated atomic utilization. However, maintaining the high-temperature stability of the Pt-1 species is of utmost importance. To answer the key question: Hydroxy- or chlorine-anchored Pt-1 single atoms in Al2O3: Which is the better choice for PDH? We have designed two types of single-atom Pt catalysts on Al2O3 via a surface group trapping strategy: Pt-1-Al2O3 with isolated Pt-O species and Pt1Cl1-Al2O3 with isolated Pt-Cl species. When tested in PDH, Pt1Cl1-Al2O3 showed an exceptional activity of 145 mol(propene) mol(Pt)(-1) min(-1) at 600 degrees C, which was 3.8 times higher than that of Pt-1-Al2O3. It has been demonstrated that the isolated Pt-Cl species in Pt1Cl1-Al2O3 act as an active site and undergoes a dehydrogenation pathway with a lower energy barrier, while Pt-1 in Pt-1-Al2O3 undergoes a dissociation-desorption pathway, resulting in few propene productions.