TY - JOUR
T1 - DEMS and RAMAN study of the monatomic hydrogen adsorption during electro-reduction of NO3- and NO2- at Pt nanoparticles supported at W18O49-ZrO2-C nanocomposite
AU - Santiago-Ramírez, C. R.
AU - Vera-Iturriaga, J.
AU - del Angel, P.
AU - Manzo-Robledo, A.
AU - Hernández-Pichardo, M. L.
AU - Soto-Hernández, J.
N1 - Publisher Copyright:
© 2020 Elsevier B.V.
PY - 2021/3
Y1 - 2021/3
N2 - A multifunctional hybrid material composed of W18O49 nanobelts (NBs), zirconium oxide, and Vulcan carbon (W18O49-ZrO2-C) has been used as support for platinum nanoparticles (PtWZC). For comparison, platinum supported on Vulcan carbon (PtC) was also synthesized. These catalysts were evaluated in the NO3- and NO2- (NOx) reduction reactions. The addition of W18O49 and ZrO2 to the carbon improved the size and distribution of the platinum nanoparticles. The electrochemical results showed that enhanced electrocatalytic activity for the NOx reduction was obtained on the PtWZC catalyst compared to PtC synthesized by the same technique and PtEtek from a commercial source. Our findings suggest that the adsorbed monatomic hydrogen (Hads) over platinum inhibits the reduction of nitrates and nitrites. Therefore, these reactions need a material that removes Hads from the surface or modifies it for the NOx reduction. The WZC support adsorbed monatomic hydrogen from water to form active bronze species (Hx-W18O49) that interacted with the NO3- and NO2- ions enabling their reduction, in accord with the results from in-situ Raman spectroscopy and Tafel slopes. N2, NO, NH3, and N2H4 products were detected in nitrite ion reduction by the Differential electrochemical mass spectrometry (DEMS) technique on the PtWZC catalyst. The production of N2 dominated in the cathodic and anodic scan. Hence, the novel catalyst can follow the indirect pathway, where the reduction process involves adsorption of NHx and adsorption of NO. The higher electrocatalytic activity obtained by the PtWZC catalyst was attributed to the uniform distribution of platinum on the support, the increased electrical conductivity produced by the W18O49 nanobelts, and the modulation of Hads on the surface.
AB - A multifunctional hybrid material composed of W18O49 nanobelts (NBs), zirconium oxide, and Vulcan carbon (W18O49-ZrO2-C) has been used as support for platinum nanoparticles (PtWZC). For comparison, platinum supported on Vulcan carbon (PtC) was also synthesized. These catalysts were evaluated in the NO3- and NO2- (NOx) reduction reactions. The addition of W18O49 and ZrO2 to the carbon improved the size and distribution of the platinum nanoparticles. The electrochemical results showed that enhanced electrocatalytic activity for the NOx reduction was obtained on the PtWZC catalyst compared to PtC synthesized by the same technique and PtEtek from a commercial source. Our findings suggest that the adsorbed monatomic hydrogen (Hads) over platinum inhibits the reduction of nitrates and nitrites. Therefore, these reactions need a material that removes Hads from the surface or modifies it for the NOx reduction. The WZC support adsorbed monatomic hydrogen from water to form active bronze species (Hx-W18O49) that interacted with the NO3- and NO2- ions enabling their reduction, in accord with the results from in-situ Raman spectroscopy and Tafel slopes. N2, NO, NH3, and N2H4 products were detected in nitrite ion reduction by the Differential electrochemical mass spectrometry (DEMS) technique on the PtWZC catalyst. The production of N2 dominated in the cathodic and anodic scan. Hence, the novel catalyst can follow the indirect pathway, where the reduction process involves adsorption of NHx and adsorption of NO. The higher electrocatalytic activity obtained by the PtWZC catalyst was attributed to the uniform distribution of platinum on the support, the increased electrical conductivity produced by the W18O49 nanobelts, and the modulation of Hads on the surface.
KW - DEMS-Surface-State
KW - In situ Raman spectroscopy
KW - NO-Reduction
KW - Pt nanoparticles
KW - WO nanobelts
KW - ZrO
UR - http://www.scopus.com/inward/record.url?scp=85091980668&partnerID=8YFLogxK
U2 - 10.1016/j.apcatb.2020.119545
DO - 10.1016/j.apcatb.2020.119545
M3 - Artículo
AN - SCOPUS:85091980668
SN - 0926-3373
VL - 282
JO - Applied Catalysis B: Environmental
JF - Applied Catalysis B: Environmental
M1 - 119545
ER -