Boosted Catalytic Performance of Ni 2 Co 2 @T-PMo@ZIF-67 for Glucose Oxidation in a Direct-Glucose Fuel Cell.

In this study, we report on how to design efficient catalysts for glucose oxidation via the transitional metal doping of nanohybrids of polyoxometalates (POMs) and metal-organic frameworks (MOFs). ZIF-67, a cobalt-based MOF, as well as phosphomolybdic acid (PMo), were used as precursors for the fabrication of pyrolyzed PMo@ZIF-67 (T-PMo@ZIF-67). A different amount of Ni²⁺ was doped into PMo@ZIF-67 to produce Ni_xCo_y@T-PMo@ZIF-67. Among them, Ni₂Co₂@T-PMo@ZIF-67 had the best performance. The power density of the fuel cell that used Ni₂Co₂@T-PMo@ZIF-67 as an anode catalyst was 3.76 times that of the cell that used active carbon as an anode catalyst. SEM and EDS mapping results indicate that Ni₂Co₂@T-PMo@ZIF-67 has a spherical structure and rough surface, and elements such as cobalt, nickel, and molybdenum are evenly distributed. XRD characterization indicates that Co₃O₄, CoMoO₄, CoNiO₄, and MoNiO₄ co-exist in the composites. It is supposed that Co²⁺, Mo⁶⁺, and Ni²⁺ in the composites may have synergistic effects on the catalytic oxidation of glucose. [ABSTRACT FROM AUTHOR]