Preparation of Pt–Ru/C as an Oxygen-Reduction Electrocatalyst in Microbial Fuel Cells for Wastewater Treatment

Gaixiu Yang,Yongming Sun,Feng Zhen,Xiaojie Chen,Pengmei Lv,Xiaoying Kong,Xinyue Cao,Zhenhong Yuan,Zhongming Wang

doi:10.3390/catal6100150

Abstract

Carbon-supported Pt–Ru alloys with a Pt/Ru ratio of 1:1 were prepared by NaBH4 reduction at room temperature. X-ray diffraction (XRD) measurements indicate that the as-prepared Pt–Ru nanoparticles had a face-centered cubic (fcc) structure. X-ray photoelectron spectroscopy (XPS) analyses demonstrate that alloying with Ru can decrease the 4f electron density of Pt, which results in a positive binding energy shift of 0.2 eV for the Pt 4f peaks. The catalytic properties of the synthesized Pt–Ru alloy catalysts were compared with those of commercial Pt/C catalysts by linear sweep voltammetry (LSV). The results show that the mass activity of the oxygen reduction reaction (ORR) is enhanced by 2.3 times as much mass activity of Pt relative to the commercial Pt/C catalyst. Single-chambered microbial fuel cell tests also confirm that the Pt–Ru alloys as cathode catalysts have better performance than that of commercial Pt/C catalysts.

Highlights

Microbial fuel cells (MFCs) are devices that convert the chemical energy stored in organic matters into electrical energy, using microorganisms as biocatalysts
The diffraction peaks around 2θ values of 40◦, 47◦, 68◦, and 82◦ could be attributed to the Pt (111), (200), (220), and (311) crystalline planes, respectively, and correspond to crystalline Pt with a face-centered cubic structure (JCPDS Card No 04-0802)
This indicates that Ru has penetrated into the Pt lattice, forming a Pt–Ru alloy in the former case [12]

Summary

Introduction

Microbial fuel cells (MFCs) are devices that convert the chemical energy stored in organic matters into electrical energy, using microorganisms as biocatalysts. In addition to producing energy, biological wastewater is treated simultaneously during the conversion process in the MFCs. During the conversion process, an electron acceptor is employed to receive the electrons transferred from the anode and complete the electrical circuit. The oxygen reduction reaction (ORR) is one of the key processes in the conversion of chemical energy to electrical energy in MFCs [1]. Owing to the sluggish kinetics of the ORR, Pt is typically used as a catalyst to accelerate the oxygen reduction process and directly transform chemical energy into electricity

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Results

Conclusion