Stability of Palladium-Polypyrrole-Foam Nickel Electrode and Its Electrocatalytic Hydrodechlorination for Dichlorophenol Isomers

Abstract

Palladium-polypyrrole-foam nickel composite electrode (Pd/PPY(PTS)/Ni) was prepared through electrodeposited of palladium nanoparticles onto preformed electrodes (surface of electrodes was coated with potentiostatic electropolymerized polypyrrole). The stability of the fresh and used composite electrode was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). It was found that the surface state, morphology, and crystalline structure of the composite electrode were stable after 5 recycle uses. Electrocatalytic activity of the composite electrode was evaluated for the hydrodechlorination (ECH) of six kinds of dichlorophenols (DCPs). Results indicated that 2,4-DCP showed higher hydrodechlorination rate. Further, the pathway of electrochemical hydrodechlorination of six kinds of dichlorophenol isomers was investigated.

Electrocatalytic Reduction-oxidation of Chlorinated Phenols using a Nanostructured Pd-Fe Modified Graphene Catalyst

“…A reduction peak at approximately À0.288 $ À0.350 V attributed to the formation of H ads was observed in all of the DPV curves. It is well known that the distribution of the electrochemical hydrodechlorination products of CPs was affected to a large extent by the position of both chlorines on the benzene ring relative to the hydroxyl group [45]. To evaluate the effect, the cathode potentials of the reductive peak from Fig.…”

Influence of environmental factors on the electrocatalytic dechlorination of 2,4-dichlorophenoxyacetic acid on nTiN doped Pd/Ni foam electrode

“…High cost of the noble metal Pd is the main obstacle for its large scale application [23], therefore many researchers have tried to support catalyst Pd on different substrate materials for the maximization of Pd catalytic effect on COCs dechlorination. Carbon materials [24], metal materials [25] and conducting polymers [26] have been extensively used as cathode substrates. Currently, Nickel (Ni) foam is being extensively applied as the cathode substrate in COCs pollution control due to its unique characteristic of high porosity and large specific surface area [27], which provides desirable modification of loaded Pd particles.…”

Pd‐Ni/Cd loaded PPy/Ti composite electrode: Synthesis, characterization, and application for hydrogen storage

“…The PPy film (Figure A) is not smooth with small and irregular spherical protuberances dispersed well on the surface of the Ti substrate, which increases the specific surface area compared with the Ti substrate. In addition, PPy comprises π‐conjugated conducting polymers, which is beneficial for dispersing the metal particles and modifying the electronic nature of the electrode . As seen in Figure B, compared with the PPy/Ti substrate, the increased amount of Cd doping resulted in a rougher surface with more intermittent porosity and cracks, which likely promotes the refinement and dispersion of Pd and Ni nanoparticles (Figure C).…”

“…In addition, based on the Scherrer formula, the metal crystallite size can be calculated: where D expresses the crystallite size of a particle (nm), K is a constant ( K = 0.89), λ = 0.15406 nm, β refers to the full width at half maximum of the corrected peak, and θ is the diffraction angle. The crystallite sizes of the metal composite are estimated to be 14.2, 13.8, 12.4, 10.0, 7.7, 9.2, and 11.1 nm for Pd 22 /Cd 78 (S1), Pd 21 ‐Ni/ 2 Cd 77 (S2), Pd 22 ‐Ni 6 /Cd 74 (S3), Pd 24 ‐Ni 9 /Cd 67 (S4), Pd 19 ‐Ni 7 /Cd 74 (S5), Pd 31 ‐Ni 5 /Cd 64 (S6), and Pd 31 ‐Ni 5 /Cd 64 (S7), respectively.…”

“…In addition, PPy comprises π-conjugated conducting polymers, which is beneficial for dispersing the metal particles and modifying the electronic nature of the electrode. 38 As seen in Figure 5B, compared with the PPy/Ti substrate, the increased amount of Cd doping resulted in a rougher surface with more intermittent porosity and cracks, which likely promotes the refinement and dispersion of Pd and Ni nanoparticles ( Figure 5C). Pd and Ni nanoparticles deposited on the Cd/PPy/Ti substrate exhibit a type of irregular popcorn structure.…”