Abatement of dichloromethane with high selectivity over defect-rich MOF-derived Ru/TiO catalysts

• Published in: Nanoscale 2022-11, Vol.14 (42), p.15724-15734
• Main Authors: Chai, Shaohua, Li, Shuangde, Zhang, Le, Fan, Guijun, Nie, Linfeng, Zhou, Xin, Yang, Wuxinchen, Li, Weiman, Chen, Yunfa
• Format: Article
• ISSN: 2040-3364; 2040-3372
• DOI: 10.1039/d2nr04261d

The regulation of oxygen vacancies and Ru species using metal-organic frameworks was synergically adopted in a rational design to upgrade Ru/TiO 2 catalysts, which are highly active for the catalytic oxidation of dichloromethane (DCM) with less undesired byproducts. In this work, Ru/M-TiO 2 and Ru/N-TiO 2 catalysts were synthesized by the pyrolysis of MIL-125 and NH 2 -MIL-125 incorporated with Ru, the existence of Ru nanoclusters and nanoparticles was detected by XAFS, respectively, and the catalytic performance was analyzed comprehensively. Complete oxidation of DCM was obtained at 290 C over Ru/M-TiO 2 and Ru/N-TiO 2 catalysts, while Ru/N-TiO 2 showed quite less monochloromethane (MCM) and higher CO 2 yields, and better dechlorination capacity in oxidation. The distinction comes down to that the easier desorption of chlorine could be achieved over Ru 4+ which act as the main activated adsorption sites for DCM in Ru/N-TiO 2 , compared to oxygen vacancies that serve as the main dissociation sites in Ru/M-TiO 2 . Additionally, Ru/N-TiO 2 exhibited superior stability and excellent resilience in moisture. An in situ DRIFTS experiment further indicated the different DCM catalytic degradation process as well as the reaction mechanism over the as-prepared catalysts. The distinction of dechlorination over activation sites with the aid of Ru/TiO 2 catalysts derived from MOFs.