Synthesis of Carbon‐Supported Pt–YO_x and PtY Nanoparticles with High Catalytic Activity for the Oxygen Reduction Reaction Using a Microwave‐based Polyol Method

Abstract

Carbon‐supported PtY alloy nanoparticles were prepared as oxygen reduction reaction (ORR) catalysts by reducing a mixture of cis‐[Pt(NH3)2(NO2)2] or Pt(C5H7O2)2 and Y(CH3COO)3⋅4 H2O in ethylene glycol (EG) with microwave (MW) heating. Microstructure and composition analyses of products by using TEM, TEM–energy‐dispersive X‐ray spectroscopy (EDS), XRD, X‐ray photoelectron spectroscopy (XPS), and inductively coupled plasma atomic emission spectroscopy (ICP‐AES) data showed that Pt–YOx/C (Y/Pt=0.11–0.75) catalysts involving amorphous yttrium oxide were formed as major products. When the YOx component in the catalysts was removed by using HNO3 treatment, Pt99.1–99.6Y0.4–0.9/C alloy catalysts with low Y contents remained. Higher ORR activity was shown by Pt–YOx/C and PtY/C catalysts than by Pt–Y(OH)3/C, Pt–YOx/C, or PtY/C catalysts prepared by using other conventional chemical reduction methods and thermal treatment methods under a H2/Ar or Ar atmosphere. The mass activity (MA) and surface specific activity (SA) of the best Pt99.5Y0.5/C catalyst, MA=245 A gPt−1 and SA=711 μA cmPt−2, were equal to or higher than those of the commercially used Pt86Co14/C catalyst, MA=245 A gPt−1 and SA=512 μA cmPt−2. The major reasons for the high ORR activity of these Pt–YOx/C and PtY catalysts are discussed. These Pt99.1–99.6Y0.4–0.9/C alloy catalysts prepared by using acid treatment are new and promising catalysts for use in proton exchange membrane fuel cells (PEMFCs).

Scalable Synthesis of Carbon-Supported Platinum–Lanthanide and −Rare-Earth Alloys for Oxygen Reduction

“…Many attempted to chemically synthesized these nanoparticles [28][29][30][31][32][33][34] , but without showing any real evidence of Pt-Y alloy formation, i.e. x-ray diffraction spectrum only showing Pt peaks and/or no x-ray photoelectron spectroscopy analysis of the Y 3d region.…”

Enhanced Photocatalytic Degradation of Methyl Orange by Au/TiO2 Nanoparticles under Neutral and Acidic Solutions

“…It has been reported that microwave (MW) heating is effective for the preparation of metallic catalysts on supports such as carbons and TiO 2 . Because carbons and metallic particles with conductive electrons absorb MW efficiently, metallic catalysts are locally heated and adsorbed strongly to support.…”

Rapid, High‐Temperature, In Situ Microwave Synthesis of Bulk Nanocatalysts

“…c) Comparison of the peak temperatures among various masses of carbon black (20, 200, and 800 mg) during microwave irradiation. d) Comparison of the heating times and temperatures demonstrated in this work with previous carbon‐black‐based microwave syntheses …”

“…Recently, microwave‐assisted synthesis has been extensively studied in carbon‐based composites . By using liquid‐phase microwave heating strategy, carbon‐supported metal, alloy and metal chalcogenide nanoparticles have been successfully fabricated, resulting in homogeneous and well‐defined nanoparticle catalysts that demonstrated enhanced performance for fuel cell applications. However, these liquid‐phase synthetic processes suffer many of the same pitfalls as that of conventional wet chemistry methods.…”