A Facile Molecular Precursor Route to Metal Phosphide Nanoparticles and Their Evaluation as Hydrodeoxygenation Catalysts

Susan E. Habas, Frederick G. Baddour, Daniel A. Ruddy, Connor P. Nash, Jun Wang, Ming Pan, Jesse E. Hensley, Joshua A. Schaidle

Research output: Contribution to journalArticlepeer-review

58 Scopus Citations

Abstract

Metal phosphides have been identified as a promising class of materials for the catalytic upgrading of bio-oils, which are renewable and potentially inexpensive sources for liquid fuels. Herein, we report the facile synthesis of a series of solid, phase-pure metal phosphide nanoparticles (NPs) (Ni2P, Rh2P, and Pd3P) utilizing commercially available, air-stable metal-phosphine complexes in a one-pot reaction. This single-source molecular precursor route provides an alternative method to access metal phosphide NPs with controlled phases and without the formation of metal NP intermediates that can lead to hollow particles. The formation of the Ni2P NPs was shown to proceed through an amorphous Ni-P intermediate, leading to the desired NP morphology and metal-rich phase. This low-temperature, rapid route to well-defined metal NPs is expected to have broad applicability to a variety of readily available or easily synthesized metal-phosphine complexes with high decomposition temperatures. Hydrodeoxygenation of acetic acid, an abundant bio-oil component, was performed to investigate H2 activation and deoxygenation pathways under conditions that are relevant to ex situ catalytic fast pyrolysis (high temperatures, low pressures, and near-stoichiometric H2 concentrations). The catalytic performance of the silica-supported metal phosphide NPs was compared to the analogous incipient wetness (IW) metal and metal phosphide catalysts over the range 200-500°C. Decarbonylation was the primary pathway for H2 incorporation in the presence of all of the catalysts except NP-Pd3P, which exhibited minimal productive activity, and IW-Ni, which evolved H2. The highly controlled NP-Ni2P and NP-Rh2P catalysts, which were stable under these conditions, behaved comparably to the IW-metal phosphides, with a slight shift to higher product onset temperatures, likely due to the presence of surface ligands. Most importantly, the NP-Ni2P catalyst exhibited H2 activation and incorporation, in contrast to IW-Ni, indicating that the behavior of the metal phosphide is significantly different from that of the parent metal, and more closely resembles that of noble metal catalysts.

Original languageAmerican English
Pages (from-to)7580-7592
Number of pages13
JournalChemistry of Materials
Volume27
Issue number22
DOIs
StatePublished - 5 Nov 2015

Bibliographical note

Publisher Copyright:
© 2015 American Chemical Society.

NREL Publication Number

  • NREL/JA-5100-64399

Keywords

  • bio-oils
  • catalytic upgrading
  • metal phospides
  • nanoparticles

Fingerprint

Dive into the research topics of 'A Facile Molecular Precursor Route to Metal Phosphide Nanoparticles and Their Evaluation as Hydrodeoxygenation Catalysts'. Together they form a unique fingerprint.

Cite this