Active Site and Electronic Structure Elucidation of Pt Nanoparticles Supported on Phase-Pure Molybdenum Carbide Nanotubes

Shuai Tan; Lucun Wang; Shibely Saha; Rebecca R Fushimi; Dongmei Li

doi:10.1021/acsami.7b01217

Active Site and Electronic Structure Elucidation of Pt Nanoparticles Supported on Phase-Pure Molybdenum Carbide Nanotubes

ACS Appl Mater Interfaces. 2017 Mar 22;9(11):9815-9822. doi: 10.1021/acsami.7b01217. Epub 2017 Mar 13.

Authors

Shuai Tan^{1

2}, Lucun Wang^{3

2}, Shibely Saha¹, Rebecca R Fushimi^{3

2}, Dongmei Li^{1

2}

Affiliations

¹ Department of Chemical Engineering, University of Wyoming , Laramie, Wyoming 82071, United States.
² Center for Advanced Energy Studies, Idaho Falls, Idaho 83401, United States.
³ Biological and Chemical Processing Department, Energy and Environment Science and Technology, Idaho National Laboratory , Idaho Falls, Idaho 83415, United States.

PMID: 28262012
DOI: 10.1021/acsami.7b01217

Abstract

We recently showed that phase-pure molybdenum carbide nanotubes can be durable supports for platinum (Pt) nanoparticles in hydrogen evolution reaction (HER). In this paper we further characterize surface properties of the same Pt/β-Mo₂C catalyst platform using carbon monoxide (CO)-Pt and CO-Mo₂C bond strength of different Pt particle sizes in the <3 nm range. Results from diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and temporal analysis of products (TAP) revealed the existence of different active sites as Pt particle size increases. Correlation between the resultant catalyst activity and deposited Pt particle size was further investigated using water-gas-shift (WGS) as a probe reaction, suggesting that precise control of particle diameter and thickness is needed for optimized catalytic activity.

Keywords: active sites; atomic layer deposition; electronic structure; molybdenum carbide; platinum; strain-ligand effect.