Hierarchical nanoporous platinum-copper (hnp-PtCu) alloy nanoflowers with bimodal pore/ligament size are easily fabricated by selectively dissolving Al atoms and part of Cu atoms from PtCuAl ternary alloy. The dealloyed samples consist of cross-linking porous nanoflowers with interconnected network skeleton and hollow channels penetrated. Hnp-PtCu alloy nanoflowers with different compositions exhibit dramatically enhanced catalytic activities toward the hydrolysis of ammonia borane (AB) compared with their monometallic components. The hnp-Pt35Cu65 alloy shows superior catalytic performance than the other hnp-PtCu catalysts with an initial much higher turnover frequency of 108 mol H-2 min(-1) (mol Pt)(-1). Moreover, the hnp-Pt35Cu65 displays excellent structure stability even after the five runs for the AB hydrolysis. The as-made hnp-PtCu catalysts hold promising application potential toward the AB hydrolysis with the advantages of facile preparation, high yielding, superior catalytic activity, and high structure durability. (C) 2017 Elsevier Inc. All rights reserved.