TY - JOUR
T1 - Electrochemical reduction of NOx species at the interface of nanostructured Pd and PdCu catalysts in alkaline conditions
AU - Soto-Hernández, J.
AU - Santiago-Ramirez, C. R.
AU - Ramirez-Meneses, E.
AU - Luna-Trujillo, M.
AU - Wang, Jin An
AU - Lartundo-Rojas, L.
AU - Manzo-Robledo, A.
N1 - Publisher Copyright:
© 2019 Elsevier B.V.
PY - 2019/12/15
Y1 - 2019/12/15
N2 - Electrochemical reduction of NOx species such as nitrates (NO3−), nitrites (NO2−), nitric oxide (NO), nitrogen dioxide (NO2) and their mixtures, was studied at the interface of palladium (Pd) and palladium-copper (PdCu) nanoparticles supported on carbon Vulcan (C). The electro-catalysts were synthesized by impregnation route with a low noble metal content of 5% wt. Pd and 2.5% wt. Pd for the mono and bi-metallic electrocatalyst, respectively. It was found by XRD analysis the formation of a solid solution in the bi-metallic catalyst and the TEM analysis suggest that the incorporation of copper decreases the particle size from 12 to 3 nm in comparison with its counterpart free of copper. Also, XPS technique verify the presence of Pd and Cu species in their metallic-oxidation states. Linear sweep and cyclic voltammetry techniques were used for the evaluation of the electrochemical NOx reduction, using alkaline solutions of NO2− or NO3− saturated with NO2 (synthesized in-situ) and NO (from commercial source). The results showed that the catalytic-activity at the current versus potential (i-E) characteristics improves significantly due to the presence of copper (as also demonstrated by CO-stripping-electrochemical active surface area calculations), inhibiting the process associated with the hydrogen evolution reaction. It is also noted in this work that the reduction faradic-current is c.a. 6 times higher at saturated solutions with NO and NO2. The NOx species were reduced mainly to nitrogen, ammonia and hydrazine as confirmed using on-line differential electrochemical mass spectrometry (DEMS) during steady-state experiments.
AB - Electrochemical reduction of NOx species such as nitrates (NO3−), nitrites (NO2−), nitric oxide (NO), nitrogen dioxide (NO2) and their mixtures, was studied at the interface of palladium (Pd) and palladium-copper (PdCu) nanoparticles supported on carbon Vulcan (C). The electro-catalysts were synthesized by impregnation route with a low noble metal content of 5% wt. Pd and 2.5% wt. Pd for the mono and bi-metallic electrocatalyst, respectively. It was found by XRD analysis the formation of a solid solution in the bi-metallic catalyst and the TEM analysis suggest that the incorporation of copper decreases the particle size from 12 to 3 nm in comparison with its counterpart free of copper. Also, XPS technique verify the presence of Pd and Cu species in their metallic-oxidation states. Linear sweep and cyclic voltammetry techniques were used for the evaluation of the electrochemical NOx reduction, using alkaline solutions of NO2− or NO3− saturated with NO2 (synthesized in-situ) and NO (from commercial source). The results showed that the catalytic-activity at the current versus potential (i-E) characteristics improves significantly due to the presence of copper (as also demonstrated by CO-stripping-electrochemical active surface area calculations), inhibiting the process associated with the hydrogen evolution reaction. It is also noted in this work that the reduction faradic-current is c.a. 6 times higher at saturated solutions with NO and NO2. The NOx species were reduced mainly to nitrogen, ammonia and hydrazine as confirmed using on-line differential electrochemical mass spectrometry (DEMS) during steady-state experiments.
KW - DEMS
KW - Electro-catalysis
KW - NO reduction-interfacial-process
KW - Nanoparticles
KW - Pollution control
UR - http://www.scopus.com/inward/record.url?scp=85070542243&partnerID=8YFLogxK
U2 - 10.1016/j.apcatb.2019.118048
DO - 10.1016/j.apcatb.2019.118048
M3 - Artículo
AN - SCOPUS:85070542243
SN - 0926-3373
VL - 259
JO - Applied Catalysis B: Environmental
JF - Applied Catalysis B: Environmental
M1 - 118048
ER -