Pompon-like Co-B alloy composed of nanosheets with a large specific surface area of 202.4 m(2) g(-1) was synthesized via a facile room-temperature solid-state-reaction. By changing the mass ratios of CoCl2.6H(2)O to CO(NH2)2 in the synthesis, the morphology of the Co-B alloy can be controlled. Correspondingly, the specific surface area can increase from ca. 43.4-202.4 m2 g-1. When the pompon-like Co-B severs as a catalyst for the hydrolysis of NaBH4, the hydrogen generation rate can be up to 8.26 L(hydrogen)min(-1) g(catalyst)(-1) This value is larger compared with those of many other Co-B nanoalloys in previous reports. Additionally, the corresponding activated energy for the hydrolytic reaction is as low as 25 kJ mol(-1), hinting that the pompon-like Co-B catalyst possesses superior catalytic performance. The pompon-like Co-B alloy has the advantages of low cost, good recoverability, as well as high activity, which may find practical application in NaBH4 hydrolysis for hydrogen production. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.