The distribution of framework Si and Al in the Cu-SSZ-13 catalyst, for NH3 selective catalytic reduction of NOx, is manipulated via a new strategy, using SAPO-34 as a seed in hydrothermal synthesis instead of the conventional SSZ-13 micro-crystallite. The SAPO-34 seed has a strong impact on the hydrothermal stability of the catalyst, moderating the dealumination as well as the agglomeration of the active Cu2+ ions in the Cu-SSZ-13 with hydrothermal treatment at 800 degrees C. (C) 2019 Elsevier Inc. All rights reserved.