STRUCTURAL CHARACTERIZATION AND ELECTROCHEMICAL PERFORMANCE OF MO4O11 AND PT-BLACK COMPOSITE USED FOR METHANOL OXIDATION

摘要

Diversified energy resources and feasible strategies are required to meet the increasing energy needs. Fuel Cells are one of the green energy sources to spontaneously convert chemical energy into electricity, releasing heat and water when electrochemical reactions occur. Recently, the direct methanol fuel cells (DMFCs) that use liquid and renewable methanol as fuel supplies have attracted significant attention. The advantages of DMFCs over hydrogen-fed fuel cells include convenient storage and transportation of fuels, high specific energy density at low operating temperature, and flexible design of the devices. However, there are several key barriers, which hinder their commercialization, such as the high cost of catalyst. One of the major barriers is the slow kinetics for methanol oxidation reaction (MOR) of the most commonly used Pt anode catalyst in DMFCs. To circumvent this problem, different kinds of co-catalytic elements, such as ruthenium, cerium and tungsten have been studied to incorporate into Pt in the last decade. The presence of the second or third elements in Pt-based catalysts could improve the MOR kinetics via a bi-functional mechanism or synergistic effect.