Deactivation mechanism of Cu active sites in Cu/SSZ-13 — Phosphorus poisoning and the effect of hydrothermal aging
Artikel i vetenskaplig tidskrift, 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

Författare

Aiyong Wang

Chalmers, Kemi och kemiteknik, Kemiteknik, Kemisk apparatteknik

Kunpeng Xie

Chalmers, Kemi och kemiteknik, Kemiteknik, Kemisk apparatteknik

Diana Bernin

Chalmers, Kemi och kemiteknik, Kemiteknik, Kemisk apparatteknik

A. Kumar

Cummins Inc.

K. Kamasamudram

Cummins Inc.

Louise Olsson

Chalmers, Kemi och kemiteknik, Kemiteknik

Applied Catalysis B: Environmental

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

Vol. 269 118781

Ämneskategorier

Oorganisk kemi

Kemiteknik

Organisk kemi

Drivkrafter

Hållbar utveckling

Styrkeområden

Transport

Fundament

Grundläggande vetenskaper

DOI

10.1016/j.apcatb.2020.118781

Mer information

Senast uppdaterat

2020-03-10