Ultrasmall and Highly Dispersed Pt Entities Deposited on Mesoporous N-doped Carbon Nanospheres by Pulsed CVD for Improved HER

Sven Küspert; Ian E Campbell; Zhiqiang Zeng; S Esmael Balaghi; Niklas Ortlieb; Ralf Thomann; Markus Knäbbeler-Buß; Christopher S Allen; Suzanne E Mohney; Anna Fischer

doi:10.1002/smll.202311260

Ultrasmall and Highly Dispersed Pt Entities Deposited on Mesoporous N-doped Carbon Nanospheres by Pulsed CVD for Improved HER

Small. 2024 Apr 18:e2311260. doi: 10.1002/smll.202311260. Online ahead of print.

Authors

Sven Küspert^{1

2}, Ian E Campbell³, Zhiqiang Zeng^{1

2

4}, S Esmael Balaghi^{2

5}, Niklas Ortlieb^{1

2

4}, Ralf Thomann^{2

5}, Markus Knäbbeler-Buß⁶, Christopher S Allen^{7

8}, Suzanne E Mohney^{3

9}, Anna Fischer^{1

2

4

5}

Affiliations

¹ Institute of Inorganic and Analytical Chemistry (IAAC), University of Freiburg, Albertstraße 21, 79104, Freiburg, Germany.
² Freiburg Materials Research Center (FMF), University of Freiburg, Stefan-Meier-Straße 21, 79104, Freiburg, Germany.
³ Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania, 16802, USA.
⁴ Cluster of Excellence livMatS, Cluster of Excellence livMatS, University of Freiburg, Freiburg, Germany.
⁵ Freiburg Center for Interactive Materials and Bioinspired Technologies (FIT), University of Freiburg, Georges-Köhler-Allee 105, 79110, Freiburg, Germany.
⁶ Fraunhofer Institute for Solar Energy Systems ISE, Heidenhofstraße 2, 79110, Freiburg, Germany.
⁷ Electron Physical Science Imaging Center, Diamond Light Source Ltd, Didcot, Oxfordshire, OX11 0DE, UK.
⁸ Department of Materials, University of Oxford, Oxford, OX1 3HP, UK.
⁹ Freiburg Institute for Advanced Studies, University of Freiburg, Albertstraße 19, 79104, Freiburg, Germany.

PMID: 38634299
DOI: 10.1002/smll.202311260

Abstract

Vapor-based deposition techniques are emerging approaches for the design of carbon-supported metal powder electrocatalysts with tailored catalyst entities, sizes, and dispersions. Herein, a pulsed CVD (Pt-pCVD) approach is employed to deposit different Pt entities on mesoporous N-doped carbon (MPNC) nanospheres to design high-performance hydrogen evolution reaction (HER) electrocatalysts. The influence of consecutive precursor pulse number (50-250) and deposition temperature (225-300 °C) are investigated. The Pt-pCVD process results in highly dispersed ultrasmall Pt clusters (≈1 nm in size) and Pt single atoms, while under certain conditions few larger Pt nanoparticles are formed. The best MPNC-Pt-pCVD electrocatalyst prepared in this work (250 pulses, 250 °C) reveals a Pt HER mass activity of 22.2 ± 1.2 A mg^-1 _Pt at -50 mV versus the reversible hydrogen electrode (RHE), thereby outperforming a commercially available Pt/C electrocatalyst by 40% as a result of the increased Pt utilization. Remarkably, after optimization of the Pt electrode loading, an ultrahigh Pt mass activity of 56 ± 2 A mg^-1 _Pt at -50 mV versus RHE is found, which is among the highest Pt mass activities of Pt single atom and cluster-based electrocatalysts reported so far.

Keywords: CO stripping; Mesoporous N‐doped carbon nanospheres; Pt clusters and single atoms; high Pt loading; hydrogen evolution reaction; pulsed chemical vapor deposition; ultrahigh mass activity.

Abstract

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