TY - JOUR

T1 - Studies on three-way catalysis with supported gold catalysts. Influence of support and water content in feed

AU - Ulrich, Viktor

AU - Moroz, Boris

AU - Sinev, Ilya

AU - Pyriaev, Pavel

AU - Bukhtiyarov, Valerii

AU - Grünert, Wolfgang

N1 - Publisher Copyright: © 2016 Elsevier B.V.

PY - 2017/4/1

Y1 - 2017/4/1

N2 - The potential of gold for the reactions of three-way catalysis was examined by converting a model exhaust consisting of 1.1% CO, 0.1% propene, 0.1% NO, O2 (0.95% - stoichiometric, 0.85% - rich, or 1.05% - lean), and water (10% or none) over catalysts containing 1–2 wt-% Au supported on Al2O3, La-Al2O3, TiO2, and CeZrOx supports. For comparison, CO and propene were also reacted stoichiometrically with oxygen in absence of further reactants, likewise, reduction of NO with CO was examined. It was found that propene is a strong poison for CO oxidation, but the intensity of the poisoning effect depended on the support (Al2O3 > La-Al2O3 > TiO2 > CeZrOx). The poisoning was strongest in dry feed but was partly alleviated in moist feed. NO was poorly converted both in the TWC mixture and in binary feed. In the model exhaust, NO conversion resulted in significant N2O formation at low temperatures, but selectivity to N2 increased with temperature. Despite poisoning by propene, Au/CeZrOx outperformed a commercial reference catalyst in CO and propene oxidation. Calcination in moist dilute air at 923 K inflicted only moderate damage to the Au catalysts. Over Au/CeZrOx, CO oxidation in stoichiometric feed was not significantly affected at all, but the poisoning effect of propene became more severe in the TWC model feed. Analogous treatment at 1223 K resulted in inacceptable damage to all reactions involved and on all supports.

AB - The potential of gold for the reactions of three-way catalysis was examined by converting a model exhaust consisting of 1.1% CO, 0.1% propene, 0.1% NO, O2 (0.95% - stoichiometric, 0.85% - rich, or 1.05% - lean), and water (10% or none) over catalysts containing 1–2 wt-% Au supported on Al2O3, La-Al2O3, TiO2, and CeZrOx supports. For comparison, CO and propene were also reacted stoichiometrically with oxygen in absence of further reactants, likewise, reduction of NO with CO was examined. It was found that propene is a strong poison for CO oxidation, but the intensity of the poisoning effect depended on the support (Al2O3 > La-Al2O3 > TiO2 > CeZrOx). The poisoning was strongest in dry feed but was partly alleviated in moist feed. NO was poorly converted both in the TWC mixture and in binary feed. In the model exhaust, NO conversion resulted in significant N2O formation at low temperatures, but selectivity to N2 increased with temperature. Despite poisoning by propene, Au/CeZrOx outperformed a commercial reference catalyst in CO and propene oxidation. Calcination in moist dilute air at 923 K inflicted only moderate damage to the Au catalysts. Over Au/CeZrOx, CO oxidation in stoichiometric feed was not significantly affected at all, but the poisoning effect of propene became more severe in the TWC model feed. Analogous treatment at 1223 K resulted in inacceptable damage to all reactions involved and on all supports.

KW - Gold

KW - Reactant interaction

KW - Support influence

KW - Three-way catalysis

KW - Water influence

KW - OXIDE

KW - AU/TIO2 CATALYSTS

KW - PERFORMANCE

KW - CO OXIDATION

KW - HYDROGEN

KW - LIQUID-PHASE OXIDATION

KW - AU CATALYSTS

KW - REDUCTION

KW - CARBON-MONOXIDE

KW - ON-ALUMINA CATALYST

UR - http://www.scopus.com/inward/record.url?scp=84992347171&partnerID=8YFLogxK

U2 - 10.1016/j.apcatb.2016.10.017

DO - 10.1016/j.apcatb.2016.10.017

M3 - Article

AN - SCOPUS:84992347171

VL - 203

SP - 572

EP - 581

JO - Applied Catalysis B: Environmental

JF - Applied Catalysis B: Environmental

SN - 0926-3373

ER -