High density ultra-small Cu nanoparticles with abundant oxygen vacancies for efficient hydrogen evolution from MeOH/H2O

Efficient release of H2 with negligible CO impurities from sustainable MeOH/H2O has become a promising goal for on-board hydrogen generator. However, hydrogen release kinetics still face challenges. In this work, the Cu/ZnO/CeO2 catalyst with high density ultra-small Cu nanoparticles and abundant oxygen vacancies were prepared for intensifying hydrogen evolution in aqueous phase reforming of methanol (APRM). The optimized 55% Cu/ZnO/CeO2 catalyst (Cu NPs of 3.8 nm, Cu loading of 55.89 wt%, oxygen vacancies of 2.316 × 1015 spins g−1) exhibited an excellent H2 evolution rate of 58.39 μmolgcat−1 s−1 even at low temperature of 210 °C, which was 2.1-fold enhancement than that of commercial Cu/ZnO/Al2O3 catalyst. Characterizations and experiments revealed that ZnO/CeO2 intensified the strong metal-support interaction (SMSI), which anchored the Cu NPs, generated abundant oxygen vacancies and adjusted electronic structure to form Cu0-Cu+-Ov active sites for facilitating the kinetics of APRM.