Ceria-Induced Strategy To Tailor Pt Atomic Clusters on Cobalt–Nickel Oxide and the Synergetic Effect for Superior Hydrogen Generation

A new and reusable hybrid catalyst of Pt/CeO₂–Co₇Ni₂O_<i>x</i> is fabricated readily, in which a high dispersion of Pt atomic cluster is successfully achieved by the introduction of CeO₂. The oxidation states of each elemental metal in varied compositions are studied systematically to design the catalyst. The optimal Pt/CeO₂–Co₇Ni₂O_<i>x</i> catalyst exhibits an extremely high specific H₂ evolution rate of 7834.8 mL_H2 min^–1 g_cat^–1 and turnover frequency of 679.0 mol_H2 min^–1 mol_Pt^–1 for the hydrolysis of alkalized NaBH₄ solution. It is one of the most efficient catalysts so far, and the reason is ascribed to the lower activation energy (47.4 kJ mol^–1) as we confirmed. The lower energy barrier and high performances mainly results from the ultrasmall Pt atomic clusters, which have more active sites to adsorb and break the B–H bonds in BH₄^– ions for the generation of negative charged H^– via electron transfer, and then the H^– can immediately combine with the positive charged H⁺ (originated from the weakened H–O–H bond on the Ce–Co–Ni oxide) to produce H₂ fast