Effective Hydrodechlorination of 4-Chlorophenol Over Pd Deposited on Multiwall Carbon Nanotubes

Dechlorination of 2,4-dichlorophenol in a hydrogen-based membrane palladium-film reactor: Performance, mechanisms, and model development

We created a hydrogen-based membrane palladium-film reactor (MPfR) by depositing palladium nanoparticles (PdNPs) on hollow-fiber membranes via autocatalytic hydrogenation to form a Pd-film. The MPfR was used for hydrodechlorination (HDC) of 2,4-dichlorophenol (2,4-DCP). HDC performances and mechanisms were systematically evaluated, and a continuous-flow dechlorination model was established. Approximately 87% of the input 2,4-DCP was reduced to the end-product phenol (P), while 2-chlorophenol (2-CP) was an intermediate, but only at 2%. Selective adsorption of the 2,4-DCP onto the Pd-film and fast desorption of P facilitated efficient dechlorination. Modeling results represented well the concentrations of 2,4-DCP and its intermediates. It demonstrated three dechlorination pathways: The majority of 2,4-DCP was completely dechlorinated to P in an adsorbed state without release of monochlorphenol, some 2,4-DCP was degraded to 2-CP that was released and subsequently adsorbed and reduced to P, and a small amount was reduced to 4-CP that was released and subsequently adsorbed and reduced to P. Analysis based on Density Functional Theory suggests that the pathway of full dechlorination was dominant due to its thermodynamically favorable adsorption configuration, with both Cl atoms bonded to Pd. This study documents full dechlorination of 2,4-DCP in the MPfR and the interacting roles of adsorption and HDC.

Catalysis of the hydrodechlorination of 4-chlorophenol and the reduction of 4-nitrophenol by Pd/Fe3O4@C

A recyclable and efficient magnetic core–shell Pd/Fe₃O₄@C nanocatalyst is applied in the HDC of 4-CP and hydrogenation of 4-NP.

Catalysis of the hydro-dechlorination of 4-chlorophenol and the reduction of 4-nitrophenol by Pd/Fe3O4@SiO2@m-SiO2

A Pd/Fe₃O₄@SiO₂@m-SiO₂catalyst with ultrahigh surface area is used in the catalysis of hydrodechlorination of 4-chlorophenol and reduction of 4-nitrophenol.

Electrospinning of palladium/silica nanofibers for catalyst applications

A new inorganic supported catalyst of silica (SiO₂)-supported palladium (Pd) nanofibers was successfully fabricated by the electrospinning followed by the calcination at high temperature and the reduction in H₂ atmosphere.

Catalysis of the hydro-dechlorination of 4-chlorophenol by Pd(0)-modified MCM-48 mesoporous microspheres with an ultra-high surface area

A Pd–MCM-48 catalyst with an ultrahigh surface area was used to catalyse the hydro-dechlorination of 4-chlorophenol.