Efficient hydrodechlorination of trichloroethylene using Pd catalysts supported on aminopropyl-functionalized SBA-15

Ultrafine Pd nanoparticles were stabilized on aminopropyl-functionalized SBA-15. • The catalyst enabled efficient FA decomposition and TCE hydrochlorination. • Successful TCE removal was achieved through FA-driven catalytic hydrogenation. Trichloroethylene (TCE), a persistent and highly toxic groundwater contaminant, demands efficient remediation strategies. Formic acid (FA, HCOOH)-assisted catalytic hydrodechlorination (HDC) is a promising approach for TCE removal, with Pd-based catalysts exhibiting excellent activity for both FA dehydrogenation and C-Cl bond hydrogenation. This study investigates an amino-functionalized SBA-15-supported Pd catalyst (Pd/SBA-15-NH 2 ) for TCE degradation in the FA-driven hydrogenation system. TEM and XPS characterization showed that the amino groups significantly enhance Pd dispersion and stabilize positively charged Pd δ+ species, furthermore in-situ DRIFTs tests conclusively confirmed that HCOO* species serve as the key intermediates in the FA dehydrogenation process, DFT study also showed Pd/SBA-15-NH 2 have lower free energy and thus improve the activity of FA dehydrogenation. Kinetic analysis confirmed a pseudo-first-order pathway with an TOF of 208.6 h −1 and apparent activation energy of 46.6 kJ/mol. Under optimized conditions (pH = 5.6, 25 °C), the catalyst achieved 100% TCE conversion in 120 min with a initial activity of 0.072 mM/(g min). Meanwhile, ethane (C 2 H 6 ) as the dominant reaction product, indicating that TCE degradation proceeds via a one-step rather than dechlorination mechanism. These findings provide valuable insights for catalytic dichlorination mechanism for chlorinated ethenes, while highlighting the theoretical foundation for the development of high-performance, noble metal-based catalysts in environmental applications. Download: Download high-res image (107KB) Download: Download full-size image