An efficient Ru/Ti oxide catalyst by facile fluorination strategy for HCl catalytic oxidation

The heterogeneous catalysis of HCl oxidation over Ru-based catalysts is a green and low-carbon chemistry route to recover high-purity Cl₂ from HCl byproduct for industrial practice. Herein, we report a facile fluorination strategy to fabricate durable supported Ru/Ti oxide catalysts for efficient HCl oxidation. The space–time yield by Ru/Ti-hf can reach up to 26.9 g_Cl2·g_cat⁻¹·h⁻¹ with an ultrahigh HCl TOF of 1.5 × 10⁴ h⁻¹. After 24-h accelerated deactivation, this catalyst exhibits over 60% higher activity compared to the conventional Ru/Ti-r. This method allows for establishing highly dispersed and sintering-resistant RuO_x species. The fluorine incorporation on TiO₂ surface generates abundant oxygen vacancies and Ru active sites, enhancing the activation capabilities for oxygen. Mechanistic calculations further suggest that the Cl-atom recombination step demanding the highest activation energy is facilitated with a lower energy barrier, due to the accumulation of electrons at the 4d orbital of Ru sites and the transfer of electron to the antibonding orbital of Ru-Cl by moderate fluorine incorporation. These findings provide a nimble approach to fabricating efficient and durable catalysts promising for HCl oxidation in industry.