TY - JOUR
T1 - Dechlorination of 2,4-dichlorophenol in a hydrogen-based membrane palladium-film reactor
T2 - Performance, mechanisms, and model development
AU - Wu, Chengyang
AU - Zhou, Luman
AU - Zhou, Yun
AU - Zhou, Chen
AU - Xia, Siqing
AU - Rittmann, Bruce E.
N1 - Funding Information:
This work is supported by National Natural Science Foundation of China (Grant No. NSFC 51678422 ) and the Fundamental Research Funds for the Central Universities.
Publisher Copyright:
© 2020
PY - 2021/1/1
Y1 - 2021/1/1
N2 - 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.
AB - 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.
KW - 2,4-dichlorophenol
KW - Hydrodechlorination
KW - Mathematical model
KW - Membrane palladium-film reactor
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U2 - 10.1016/j.watres.2020.116465
DO - 10.1016/j.watres.2020.116465
M3 - Article
C2 - 33049566
AN - SCOPUS:85092255711
SN - 0043-1354
VL - 188
JO - Water Research
JF - Water Research
M1 - 116465
ER -