Highly efficient and stable BaF₂-supported Ru catalyst for CFC-113a hydrogenation coupling reaction

The development and synthesis of novel environmentally-friendly chlorofluorocarbon alternatives are in accordance with the global sustainability paradigm and represent a progressive response to contemporary technological demands. 2,3-dichloro-1,1,1,4,4,4-hexafluoro-2-butene (CFC-1316mxx) holds significant research value as a synthetic intermediate for the novel environmentally-friendly chlorofluorocarbon alternative 1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336mzz). This study developed a Ru/BaF₂ catalyst based on BaF₂ as the support for the hydrogenation coupling of 1,1,1-trifluorotrichloroethane (CFC-113a) to synthesize CFC-1316mxx. The physical/chemical properties of Ru/BaF₂ before and after reaction were analyzed by methods of XRD, BET, SEM, TEM, XPS, TG, H₂-TPR, and NH₃-TPD, and its catalytic performance in the reaction was also evaluated. Ru/BaF₂ features suitable acidity, adequate reducibility, appropriate specific surface area and pore structure, and exceptional thermal stability. Moreover, Ru/BaF₂ exhibits excellent catalytic activity, selectivity and stability, with a CFC-113a conversion rate of 93.81 % and a CFC-1316mxx selectivity of up to 96.04 %. As BaF₂ may also act as a “chlorine absorber” to inhibit catalyst deactivation, the conversion rate can remain at 71.00 % with a high selectivity of 95.21 % after 100 h of use. Based on the structural analysis of catalysts and the distribution of products, the reaction mechanism was also speculated.