Protective sulfur removal system for enhanced methane slip catalysts in sulfur-containing exhaust

A method of manufacturing a sulfur trap article, the method comprising:

• (a) preparing a washcoat slurry comprising zeolite, a cerium-oxide material, and alumina;
• (b) coating the slurry onto a monolithic honeycomb substrate to form a washcoat layer;
• (c) applying a second coating layer comprising copper, manganese, and cerium metal precursors;
• and
• (d) calcining the coated substrate to form a sulfur trap article configured to adsorb sulfur dioxide.

An exhaust aftertreatment system comprising:

• (a) an exhaust line receiving exhaust gas from a methane containing combustion device;
• (b) a sulfur trap article positioned as a first functional treatment device downstream of the exhaust manifold, the sulfur trap article comprising:
• (i) a washcoat layer containing zeolite, ceria-containing material, and alumina;
• and
• (ii) copper, manganese, and cerium metal oxide compounds doped onto the washcoat;
• and
• (c) a methane oxidation catalyst positioned downstream of the sulfur trap, wherein the sulfur trap reduces sulfur dioxide concentration to a level that prevents sulfur poisoning of the methane oxidation catalyst.