4A Zeolite Support for Pt Nanoparticles towards Methanol Oxidation

Abstract

The effect of 4A zeolite as a support on the electrocatalytic activity of Pt nanoparticles for the oxidation of methanol has been investigated. Pt/4A zeolite and Pt/C catalysts with the same mass of Pt are prepared by loading the Pt nanoparticles stabilized by PEG-400 on 4A zeolite and carbon black, respectively. Physical analyses reveal unevenly distributed but no large agglomerates of the Pt nanoparticles on the surface of 4A zeolite due to PEG-400 attached to the Pt nanoparticles, while the Pt nanoparticles on carbon black show a uniform distribution and a lesser degree of agglomeration. However, Pt/4A zeolite shows a much more negative onset potential and a significantly higher peak current density than Pt/C in methanol oxidation in both acidic and alkaline solutions. Pt/4A zeolite also shows high resistance to the poisoning caused by CO-like species formed in the reaction. The results indicate that 4A zeolite is superior to carbon black as a support for the Pt nanoparticles toward methanol oxidation, and further suggest that some types of zeolites could be used as efficient support materials in electrocatalysis.

Bimetallic PtCu Nanocrystal Sensitization WO3 Hollow Spheres for Highly Efficient 3-Hydroxy-2-butanone Biomarker Detection

“…The peaks with binding energies at 932.4/952.2 eV and 934.2/954.3 eV correspond to Cu 0 and Cu 2+ , respectively . Similarly, the Pt 4f XPS spectra of PtCu/WO 3 HS could also be ascribed to Pt 0 (70.3 eV/73.6 eV) and Pt 2+ (71.2 eV/74.3 eV), respectively. , The peak at 75.1 eV is representative of metallic Cu 3p 3/2 in the nanocomposite …”

“…45 Similarly, the Pt 4f XPS spectra of PtCu/WO 3 HS could also be ascribed to Pt 0 (70.3 eV/73.6 eV) and Pt 2+ (71.2 eV/74.3 eV), respectively. 45,46 The peak at 75.1 eV is representative of metallic Cu 3p 3/2 in the nanocomposite. 47 3.2.…”

Electrocatalytic Activity of Au Supported on Carbon Black‒4A Zeolite for Propane-1,2-Diol Oxidation

“…5 is not a low value when considering the concentration of propane-1,2-diol, the Au loading and scan rate. This, together with the high catalytic activity of Pt/4A-Z compared to Pt/C for methanol oxidation, 16 indicates that in the electrolyte solution the electrical conductivity of 4A zeolite is not a limiting factor for its application as a support material.…”

“…5,15,29,30 For Au/C-4A-Z(2:1) and Au/4A-Z, however, no peaks of 4A zeolite are observed and the reasons are not clear. No XRD peaks of 4A zeolite were also reported for Pt/4A-Z (20 wt% Pt) prepared by depositing the Pt nanoparticles on 4A zeolite 16 and Pt/4A-Z (3.9 wt% Pt) prepared by encapsulating the Pt nanoparticles within 4A zeolite. 5 On the other hand, high diffraction peaks of 4A zeolite and no diffraction peaks of Au were reported for Au/4A-Z prepared by encapsulating the Au nanoparticles within Na-LTA zeolite, 15 and high diffraction peaks of 4A zeolite and low diffraction peaks of Pt and Ag were reported for Pt/4A-Z and Ag/4A-Z prepared by depositing Pt or Ag nanoparticles on 4A zeolite.…”

“…5 In our previous work, the Pt/4A-Z catalyst with a 20 wt% Pt, prepared by depositing the Pt nanoparticles on the surface of 4A zeolite, showed high catalytic activity for the electrooxidation of methanol in alkaline and acidic solutions. 16 The catalytic performance of Au in the electrooxidation of alcohol is interesting. For glycerol oxidation, for instance, Au shows very low catalytic activity in acidic medium but high catalytic activity in alkaline medium.…”