A NOx abatement system comprising: a first NOx adsorber (18) capable of being disposed in-line and downstream of and in fluid communication with an engine (12); a selective catalytic reduction catalyst (20) disposed in-line and downstream of and in direct fluid communication with the first NOx adsorber (18), wherein the selective catalytic reduction catalyst (20) is capable of storing ammonia; and an off-line reformer (24) disposed in selective communication with and upstream of the first NOx adsorber (18) and the selective catalytic reduction catalyst (20), wherein the reformer (24) is capable of producing a reformate comprising primarily hydrogen and carbon monoxide.