Conversion of Dimethyl Ether to 2,2,3-Trimethylbutane over a Cu/BEA Catalyst: Role of Cu Sites in Hydrogen Incorporation

Joshua Schaidle, Daniel Ruddy, Susan Habas, Jesse Hensley, Guanghui Zhang, Jeffrey Miller

Research output: Contribution to journalArticlepeer-review

34 Scopus Citations

Abstract

Recently, it has been demonstrated that methanol and/or dimethyl ether can be converted into branched alkanes at low temperatures and pressures over large-pore acidic zeolites such as H-BEA. This process achieves high selectivity to branched C4 (e.g., isobutane) and C7 (e.g., 2,2,3-trimethylbutane) hydrocarbons. However, the direct homologation of methanol or dimethyl ether into alkanes and water is hydrogen-deficient, resulting in the formation of unsaturated alkylated aromatic residues, which reduce yield and can contribute to catalyst deactivation. In this paper we describe a Cu-modified H-BEA catalyst that is able to incorporate hydrogen from gas-phase H2 cofed with dimethyl ether into the desired branched alkane products while maintaining the high C4 and C7 carbon selectivity of the parent H-BEA. This hydrogen incorporation is achieved through the combination of metallic Cu nanoparticles present on the external surface of the zeolite, which perform H2 activation and olefin hydrogenation, and Lewis acidic ion-exchanged cationic Cu present within the H-BEA pores, which promotes hydrogen transfer. With cofed H2, this multifunctional catalyst achieved a 2-fold increase in hydrocarbon productivity in comparison to H-BEA and shifted selectivity toward products favored by the olefin catalytic cycle over the aromatic catalytic cycle.

Original languageAmerican English
Pages (from-to)1794-1803
Number of pages10
JournalACS Catalysis
Volume5
Issue number3
DOIs
StatePublished - 2015

Bibliographical note

Publisher Copyright:
© 2015 American Chemical Society.

NREL Publication Number

  • NREL/JA-5100-63652

Keywords

  • aromatic catalytic cycle
  • Cu/H-BEA
  • dimethyl ether
  • H-BEA
  • homologation
  • hydrogen incorporation
  • olefin catalytic cycle
  • triptane
  • zeolite

Fingerprint

Dive into the research topics of 'Conversion of Dimethyl Ether to 2,2,3-Trimethylbutane over a Cu/BEA Catalyst: Role of Cu Sites in Hydrogen Incorporation'. Together they form a unique fingerprint.

Cite this