Characterization of Active Species in Cu-Beta Zeolite by Temperature-Programmed Reduction Mass Spectrometry (TPR-MS)
Journal article, 2013

The number and type of copper species present in an under-exchanged Cu-Beta zeolite catalyst were characterized using temperature-programmed reduction mass spectrometry (TPR-MS). Both H-2 consumption and H2O evolution were tracked, yielding additional insights into the nature of Cu species. Prior to the TPR-MS tests, catalyst samples were subjected to various high- temperature aging treatments in the presence of O-2 in He, in order to assist with interrogating and resolving different types of sites. Absence of reducible species in the precursor material was confirmed by subjecting the H-form of the same zeolite to the TPR. Upon aging at temperatures below 700 A degrees C, the TPR pattern showed several distinct peaks of different intensities. Aging at 800 A degrees C led to shifting and broadening of these H-2 consumption peaks, as well as to some reduction of the integral amount of the reducible sites. The 900 A degrees C exposure resulted in a drastic change of the TPR pattern, with several new well-resolved H-2 consumption peaks, indicative of drastic changes in the catalyst structure. The integral amount of H-2 consumed quantitatively matched the amount of Cu species present in the catalyst, assuming the stoichiometry. The combination of experimental findings in this work lends support to a hypothesis that different TPR peaks are indicative of different types of sites rather than of step-wise reduction of copper species.

Cu-zeolite

Beta-zeolite

SCR

Temperature-programmed reduction

Author

J. H. Li

Cummins Inc.

Norman Wilken

Chalmers, Chemical and Biological Engineering, Chemical Reaction Engineering

Competence Centre for Catalysis (KCK)

K. Kamasamudram

Cummins Inc.

N. W. Currier

Cummins Inc.

Louise Olsson

Competence Centre for Catalysis (KCK)

Chalmers, Chemical and Biological Engineering, Chemical Reaction Engineering

A. Yezerets

Cummins Inc.

Topics in Catalysis

1022-5528 (ISSN) 1572-9028 (eISSN)

Vol. 56 1-8 201-204

Areas of Advance

Transport

Subject Categories

Physical Chemistry

DOI

10.1007/s11244-013-9952-1

More information

Created

10/7/2017