Application of SnO_x/AC catalyst for the acetylene hydrochlorination

In this work, SnO_x/activated carbon (AC) was synthesized by hydrothermal method, which was applied to acetylene hydrochlorination. Characterizations showed the SnO_x nanoparticles were uniformly dispersed on the carbon, with the co-existence of SnO and SnO₂. The acetylene conversion of SnO_x/AC was 75%, much higher than that of SnCl₄/AC. It was shown that the adsorption of reactants on SnO_x was stronger than on SnCl₄. Theoretical calculations showed the adsorption energies of reactants on SnO_x were thermodynamically favorable and suggested that Sn⁴⁺ and Sn²⁺ in SnO_x have different adsorption capacities for reactants. Through adjusting the valence ratio of SnO_x, SnO_x/AC O 4 h (O for oxidation) exhibited the best catalytic performance and had the strongest adsorption capacity for the reactants. However, the SnO_x/AC catalyst was easily deactivated during acetylene hydrochlorination due to the loss of Sn. The doping of N effectively reduced the loss of Sn and improved the stability of the catalyst due to the anchoring effect of N on the SnO_x particles.