The invention relates to the possibility of improving selective catalytic reduction (SCR), which is the selective reaction of nitrogen oxides with ammonia in the exhaust gas of combustion processes on an exhaust-gas catalytic converter suitable therefor - the SCR catalytic converter. For this purpose, materials used in the catalytic converter for storing ammonia are distributed on the catalyst carrier in such a way that, viewed in the flow direction, a region having low ammonia storage capacity is followed by a region of higher ammonia storage capacity.