Effect of the Transforming Ag into an Active Species (Silver Chloride) for the Acetylene Hydrochlorination

Abstract Effective approaches are desired to improve catalytic performances for the hydrochlorination of acetylene. Crucially, the systematic explorations of catalytic and deactivation mechanisms are prerequisites to the implementation of such approaches. Ag has been scarcely researched for acetylene hydrochlorination reaction because it is easily poisoned by Cl, which inactivates it. However, this challenge must be further verified. Here, the active species and causes of the deactivation of Ag/activated carbon (AC) were discussed in detail. The results indicated that Ag/AC exhibited excellent catalytic performance in the acetylene hydrochlorination. Specifically, X‐ray photoelectron spectroscopy (XPS) analysis revealed that AgCl was the main active site, which was almost transformed from Ag 0 after the activation with HCl for 0.5 h. Moreover, inductively coupled plasma optical emission spectrometer (ICP‐OES) and transmission electron microscopy (TEM) results confirmed that the deactivation of the catalyst was justified by the loss of Ag and particle aggregation. Thus, the conversion of acetylene of the small‐sized AgCl nanoparticles were significantly enhanced, and these inhibited the agglomeration of the particles, thereby further verifying that AgCl was the active site. This perspective offered a suitable insight for the subsequent research on Ag‐based catalysts.