Systems and methods for selective catalytic reduction and/or ammonia slip catalyst sulfur protection

A method, comprising:

• predicting a sulfur exposure of one or more copper-zeolite catalysts deployed in an exhaust aftertreatment system;
• comparing the predicted sulfur exposure to a predefined sulfur exposure threshold, the predefined sulfur exposure threshold being an amount of sulfur present in the exhaust gas for a first predefined time period, wherein the predefined sulfur exposure threshold is greater than 1 gram of sulfur per liter of exhaust gas (gS/L);
• receiving a fault code indicating that a NOx amount in exhaust gas leaving the exhaust aftertreatment system is above a predefined high NOx amount threshold;
• in response to the comparison indicating that the predicted sulfur exposure of the one or more copper-zeolite catalysts is at or above the predefined sulfur exposure threshold and receiving the fault code, heating the one or more copper-zeolite catalysts to a predefined heat treatment temperature to desulfate the one or more copper-zeolite catalysts;
• starting a timer in response to a temperature of the heated one or more copper-zeolite catalysts increasing by a predefined amount;
• and
• stopping the heating of the one or more copper-zeolite catalysts based on the timer indicating that a second predefined time period has elapsed, wherein the second predefined time period is based on the predefined heat treatment temperature.