Toward the Continuous Production of Multigram Quantities of Highly Uniform Supported Metallic Nanoparticles and Their Application for Synthesis of Superior Intermetallic Pt-Alloy ORR Electrocatalysts.

Luka Pavko,Francisco Ruiz-Zepeda,Janez Križan,Mitja Kostelec,Ivan Jerman,Moritz Geuß,Pascal Kaiser,Gregor Križan,Marjan Bele,Tina Đukić,Boštjan Genorio,Matija Gatalo,Martin Šala,Konrad Ehelebe,Serhiy Cherevko,Nigel Van De Velde,Goran Dražić,Miran Gaberšček,Nejc Hodnik

doi:10.1021/acsaem.1c02570

Abstract

A fast and facile pulse combustion (PC) method that allows for the continuous production of multigram quantities of high-metal-loaded and highly uniform supported metallic nanoparticles (SMNPs) is presented. Namely, various metal on carbon (M/C) composites have been prepared by using only three feedstock components: water, metal–salt, and the supporting material. The present approach can be elegantly utilized also for numerous other applications in electrocatalysis, heterogeneous catalysis, and sensors. In this study, the PC-prepared M/C composites were used as metal precursors for the Pt NPs deposition using double passivation with the galvanic displacement method (DP method). Lastly, by using thin-film rotating disc electrode (TF-RDE) and gas-diffusion electrode (GDE) methodologies, we show that the synergistic effects of combining PC technology with the DP method enable production of superior intermetallic Pt–M electrocatalysts with an improved oxygen reduction reaction (ORR) performance when compared to a commercial Pt–Co electrocatalyst for proton exchange membrane fuel cells (PEMFCs) application.

Highlights

Metallic nanoparticles (NPs) are spearheading the nextgeneration material science revolution, mainly in the fields of heterogeneous catalysis[1] and electrocatalysis[2] as well as in the fields of supercapacitors,[3] sensors,[4] and others.[5]
As part of this work, we have focused mainly on metal on carbon (M/C) composites (M = Cu, Co, or Ni; C = commercial carbon blacks or reduced graphene oxide support (rGO))
In the second part we presented a use case for M/C composites by preparing Pt-alloy oxygen reduction reaction electrocatalysts for the use in proton exchange membrane fuel cells

Summary

■ INTRODUCTION

Metallic nanoparticles (NPs) are spearheading the nextgeneration material science revolution, mainly in the fields of heterogeneous catalysis[1] and electrocatalysis[2] (e.g., proton exchange membrane fuel cells; PEMFCs) as well as in the fields of supercapacitors,[3] sensors,[4] and others.[5]. The last cleaning step composed of redispersing GO in Milli-Q water and soaking until the day, followed by again centrifugation at 10500 rpm for 1 h to discard the supernatant This has been repeated four more times, adding up to total of five washing cycles with MilliQ. Black EC300J) via double passivation galvanic displacement method reported elsewhere.[12] Briefly, the Pt deposition step consists of less noble metal (M) oxide passivation followed by carbon monoxide (CO) capping of Pt-based NPs formed by galvanic displacement of M after Pt-salt addition. Before experiments with new catalysts or electrolyte, the half-cell was cleaned by boiling in 1% HNO3 solution (65% EMSURE, Merck) for 1 h Afterward, it was boiled in ultrapure water (Milli-Q, Merck) five times. Thereby impedance was measured at each current step as previously reported.[27,28] All experiments were conducted under ambient conditions (101 kPa, 20 °C) and repeated three times

■ RESULTS AND DISCUSSION

■ CONCLUSION

■ ACKNOWLEDGMENTS

■ REFERENCES