Carbon-supported binary Li-Sn catalyst for acetylene hydrochlorination

The study of a novel catalyst containing LiCl and SnCl₂ (LiSn/AC) for acetylene hydrochlorination has been reported in this paper. Furthermore, the performance of both high activity (98.3%) and selectivity (>98.0%) are achieved by LiSn/AC catalysts under the reaction temperature of 200 °C and C₂H₂ hourly space velocity of 30 h^?1. The structural characteristics of the Sn based catalysts were deeply researched via BET, XRD, TEM, TPR, C₂H₂-TPD, XPS and TG techniques. According to these characteristic results, we proposed that the presence of Sn²⁺ exhibited better activity and stability than that of Sn⁴⁺ in Sn based catalysts. Additionally, LiCl additives not only can restrain the oxidation of Sn²⁺ and the loss of Sn⁴⁺ in fresh Sn based catalysts but also make the Sn^δ+ (δ = 2,4) species dispersed well on the surface of support. Therefore, the adsorption capacity of C₂H₂ and HCl was enhanced in LiSn/AC, which exhibited the better catalytic performance than that of Sn based catalyst.