Deactivation mechanism of Cu active sites in Cu/SSZ-13 — Phosphorus poisoning and the effect of hydrothermal aging
Journal article, 2020

Non-poisoned and P-poisoned Cu/SSZ-13 catalysts with different types of Cu sites, i.e., [Cu(OH)]+ and Cu2+, were investigated for NH3-SCR. Phosphorus was found to interact more with [Cu(OH)]+ than Cu2+. Moreover, less phosphorus was required per Cu for poisoning in the samples with a high content of [Cu(OH)]+. We propose a phosphorus poisoning mechanism based on H2-TPR and XPS: poisoning of one Cu2+ involved two P atoms, i.e., P2O5, but for [Cu(OH)]+ contamination, only one P atom (PO3− or PO43−) is needed. Furthermore, phosphorus poisoning resulted in a decline in NH3/NO oxidation and an improvement in SCR activity at high temperatures. Upon hydrothermal aging, [Cu(OH)]+−phosphate/metaphosphate complexes were likely easier detached from the framework than the Cu2+−P2O5 species. This resulted in that the P-poisoned catalyst with high content [Cu(OH)]+ experienced more severe deactivation and dealumination than the non-poisoned catalyst. Additionally, 27Al-NMR suggested that the formation of AlPO4 has a linear relationship with [Cu(OH)]+/Cu2+ ratios.

Phosphorus-poisoned

Hydrothermal aging

SCR

Cu/SSZ-13

Zeolite

Author

Aiyong Wang

Chalmers, Chemistry and Chemical Engineering, Chemical Technology, Chemical Engineering Design

Kunpeng Xie

Chalmers, Chemistry and Chemical Engineering, Chemical Technology, Chemical Engineering Design

Diana Bernin

Chalmers, Chemistry and Chemical Engineering, Chemical Technology, Chemical Engineering Design

A. Kumar

Cummins Inc.

K. Kamasamudram

Cummins Inc.

Louise Olsson

Chalmers, Chemistry and Chemical Engineering, Chemical Technology

Applied Catalysis B: Environmental

0926-3373 (ISSN) 1873-3883 (eISSN)

Vol. 269 118781

Subject Categories

Inorganic Chemistry

Chemical Engineering

Organic Chemistry

Driving Forces

Sustainable development

Areas of Advance

Transport

Roots

Basic sciences

DOI

10.1016/j.apcatb.2020.118781

More information

Latest update

3/10/2020