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直接甲醇燃料电池(DMFC)具有功率密度高、能量转化效率高和燃料易于携带等优点,是一种极具竞争潜力的便携式、可移动能源。然而,DMFC商业化尚存在一些问题。就阴极而言:一是阴极催化剂高的过电位和高的Pt用量;二是透过质子交换膜从阳极渗透到阴极的甲醇造成阴极“混合电位”效应,导致阴极过电位增加了0.2～0.3 V,电池效率下降约1/3。核壳结构的双金属催化剂作为一种新型催化剂,它具有包覆层金属和金属核的双层物化性能,不仅拥有合金型催化剂的反应活性和选择性,而且在酸性介质中可以避免过渡金属的溶解,使得催化剂的性能得到改善。开发并研究核壳型的电催化剂是减小混合过电位、降低电池成本的重要手段。
Direct methanol fuel cell (DMFC) has the advantages of high power density, high energy conversion efficiency and easy transport of fuel, which is a very competitive and portable energy source. However, some problems still exist in the commercialization of DMFC. In terms of the cathode: one is the high overpotential and the high Pt content of the cathode catalyst; the other is that the methanol permeating through the proton exchange membrane from the anode to the cathode causes the cathode “mixed potential” effect, resulting in an increase of 0.2 ~ 0.3 V, battery efficiency decreased by about 1/3. As a new type of catalyst, the bimetallic catalyst with core-shell structure has the bilayer physicochemical properties of the cladding metal and the metal core. It not only possesses the reactivity and selectivity of the alloy catalyst, but also can avoid the transition metal Dissolved, so that the performance of the catalyst is improved. Developing and studying the core-shell electrocatalyst is an important means to reduce the mixing overpotential and reduce the battery cost.