Abstract: A system comprising a fuel converter comprising a catalyst composition capable of converting a fuel into a selected one or both of a syngas reductant and a short chain hydrocarbon reductant, wherein the catalyst composition comprises: cracking sites that perform a cracking function when a temperature of an exhaust fluid is greater than a predetermined threshold temperature, wherein the cracking function converts long chain hydrocarbon molecules to short chain hydrocarbon molecules; and partial oxidation sites that perform a catalytic partial oxidation function when the temperature of the exhaust fluid is less than the predetermined threshold temperature, wherein the catalytic partial oxidation function oxidizes the fuel to produce the syngas reductant; and a selective catalytic reduction catalyst reactor in fluid communication with the fuel converter and the exhaust fluid.