Nickel multiply-twinned particles (Ni MTPs) imbedded onto ZSM-5 were prepared, and their formation and chemical and electronic properties were characterized by HRTEM, XPS, CO-FTIR, and H-2-TPD. HRTEM showed the formation of Ni MTPs with triangular, square, hexagonal, and spherical shapes. The multiply-twinned particles were composed of f.c.c. nanocrystals dominated by (111) crystal face. Ni MTPs indicate an enhanced CO adsorption capability as compared with ordinary Ni particles. Ni MTPs were electron deficient and inherently strained, which is responsible for high catalytic activity in the hydrolytic hydrogenation of cellulose. (C) 2015 Elsevier Inc. All rights reserved.