Improved low-temperature activity of silver-alumina for lean NOx reduction–effects of Ag loading and low-level Pt doping
Journal article, 2014

This study focuses on the effect of silver loading and low-level platinum doping on the distribution of silver species, the hydrocarbon activation, and the low-temperature activity for lean NOx reduction over silver-alumina catalysts. Sol-gel prepared Ag/Al2O3 samples, with varying silver loading and doped with trace amounts of platinum, were evaluated as HC-SCR catalysts using n-octane as reductant in a synthetic gas-bench reactor. In addition, the samples were characterized using X-ray photoelectron spectroscopy, ultraviolet visible spectroscopy, and the specific surface area was determined using nitrogen sorption. The study shows that as the samples are doped with trace-amounts of platinum, the activity for lean NOx reduction at low temperatures is enhanced. The catalyst composition that displays the highest activity for NOx reduction is a 2 wt% Ag/Al2O3 sample doped with 500 ppm platinum. This catalyst displays the highest low-temperature activity, most likely owing to an increased ability to adsorb and partially oxidize the hydrocarbon reductant, which is attributed to the Pt doping. Adsorption of a higher amount of hydrocarbons could result in that a lower amount of reducing agent is required for Pt doped Ag-alumina catalysts as compared to un-doped ones, which is beneficial with respect to fuel efficiency.

Lean NOx reduction

Ag/Al2O3

Platinum doping

Silver-alumina

HC-SCR

Author

Fredrik Gunnarsson

Competence Centre for Catalysis (KCK)

Chalmers, Chemical and Biological Engineering, Applied Surface Chemistry

Hannes Kannisto

Chalmers, Chemical and Biological Engineering, Applied Surface Chemistry

Competence Centre for Catalysis (KCK)

Magnus Skoglundh

Chalmers, Chemical and Biological Engineering, Applied Surface Chemistry

Competence Centre for Catalysis (KCK)

Hanna Härelind

Competence Centre for Catalysis (KCK)

Chalmers, Chemical and Biological Engineering, Applied Surface Chemistry

Applied Catalysis B: Environmental

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

Vol. 152-153 1 218-225

Driving Forces

Sustainable development

Areas of Advance

Nanoscience and Nanotechnology (2010-2017)

Transport

Energy

Materials Science

Subject Categories

Physical Chemistry

Chemical Process Engineering

Materials Chemistry

DOI

10.1016/j.apcatb.2014.01.043

More information

Created

10/8/2017